With e-cigarettes and flavored vapes booming in popularity, the U.S. Supreme Court on Monday will examine whether the Food and Drug Administration unlawfully blocked the marketing and sale of more than a million new sweet and candy-flavored nicotine products in recent years.

The Supreme Court is scheduled Monday to consider the regulation of flavored e-cigarettes in a case that illustrates an enduring public health conundrum: how to keep kids away from sweet-flavored, addictive vapes while giving adult smokers better options to help them quit cigarettes.