Here is a look at some of the stories that CNN plans to follow this week:
Supreme Court tackles health care law
The U.S. Supreme court is about to take on what legal observers say is one of the most important cases it has heard in years: the 2010 health care reform law.
The court will hear oral arguments Monday through Wednesday on the law's constitutionality. The court's eventual rulings this year will "not only guide how every American receives medical care but would also establish precedent-setting boundaries of government regulation over a range of social areas," CNN Supreme Court Producer Bill Mears writes.
Among the key issues: The constitutionality of the individual mandate - the requirement ofÂ nearly every American to purchase some level of insurance or face a tax penalty of up to about $700 a year; and whether other parts of the law can survive if the mandate is struck down.
The law, among other things, wasÂ designed to help millions of uninsured and underinsured Americans receive adequate and affordable health care through a series of government-imposed mandates and subsidies. The federal government will tell the court that 45 million Americans last year lacked health coverage, roughly 15% of the country's population.
Critics have equated the measure to socialized medicine, fearing that a bloated government bureaucracy will result in higher taxes and diminished health care services.
Ahead of nuclear summit, concern over North Korea's planned missile launch
Top officials from 54 countries will meet in South Korea on Tuesday for an international nuclear security summit to discuss how to secure the world's nuclear material and prevent nuclear terrorism. U.S. President Barack Obama will attend.
The message of international cooperation, however, is being somewhat overshadowed by grumblings over North Korea's planned launch next month of a long-range missile, which North Korea says is to carry a satellite into space.
South Korea has said it considers the satellite launch an attempt to develop a nuclear-armed missile, and that the launch would violate a U.N. Security Council resolution that bans the testing of the technology being used in the rocket-powered satellite. The United States has warned the move would jeopardize a food-aid agreement reached with Pyongyang in early March. In that deal, North Korea agreed it would not carry out nuclear or missile tests in return for food aid.
North Korea says it has a right to a peaceful space program and has invited international space experts and journalists to witness the launch.
Seoul's nuclear summit will be the second after Obama hosted the first meeting in Washington in 2010. He initiated the biennial summit after presenting his vision of a nuclear-free world in Prague in April 2009.
Protest over Trayvon Martin killing expected in Sanford, Florida
Among the rallies that are planned this week to protest last month's killing of an unarmed black Florida teenager, one is expected to be held Monday outside the site of a city commissioners' meeting in Sanford, where the 17-year-old was shot.
Trayvon Martin was unarmed when he was shot and killed by a neighborhood watch volunteer while walking home from a convenience store on February 26, according to police.
George Zimmerman, who police said was the man who killed Martin, claimed he did so in self-defense. Zimmerman, a white Hispanic, has not been arrested or charged in the killing of the teenager, sparking a national debate over Florida's "stand your ground" deadly force law amid concerns about racial profiling.
The Sanford Police Department said officers were prohibited from arresting Zimmerman the night of the shooting because physical evidence and testimony supported his claim that he acted in self-defense in accordance with Florida law. Zimmerman's attorney says his client was injured that night and went to the hospital with a broken nose and a serious cut on the back of his head.
The state prosecutor investigating Martin's death has said her office has the power to charge Zimmerman, clear him or send the case to a grand jury.
Congress faces Saturday deadline to end transportation standoff
Thousands of road and bridge construction projects will be in jeopardy if Congress doesn't pass some type of transportation funding measure by Saturday.
The Democratic-led Senate already has passed a two-year, $109 billion bill. But the Republican-controlled House has not moved on it, due in part to their sharply different views aboutÂ the overall expense of the bill and how to pay for it.
Last week, House Transportation Committee Chairman John Mica, R-Florida, said the House would soon pass a three-month extension of existing funding to provide time for negotiations over a longer-term bill.Â Senate Majority Leader Harry Reid, D-Nevada, said heÂ was "inclined not to" pass a temporary funding extension.
But House passage of a temporary bill could put Democrats under enormous pressure not to let funding dry up. Failure to pass any funding measure would allow thousands of construction jobs to go idle.
With pope's visit, Cuba's complex relationship with Catholic Church on display
On Monday, Pope Benedict XVIÂ is scheduled to make only the second papal visit to Cuba, and the first since Pope John Paul II went to the communist nation in 1998.
After decades of chilly relations between the church and Cuban government, including the near dismantling of Cubaâ€™s Catholic Church in the 1960s, the regime is rolling out the welcome mat for the popeâ€™s visit. But is the leader of the global Roman Catholic Church receiving more than just lip service from the secular and once officially atheist Cuban state? Patrick Oppmann, CNNâ€™s correspondent based in Havana, explores the complex answer in a post on CNN.com's Belief Blog.
March Madness gets down to Final Four
The NCAA men's basketball tournament has whittled the field down from 68 teams to just four. Those teams will square off next weekend in New Orleans.
Kentucky crushed Baylor 82-70 Sunday afternoon to join Ohio State and Louisville in the Final Four. The fourth finalist is Kansas; the Jayhawks defeated North Carolina 80-67 later Sunday in St. Louis.
Kentucky will play Louisville and Ohio State will play Kansas on Saturday, with the winners meeting for the national championship on Monday, April 2.