Medicine 7 hours ago American scientists win Nobel Prize for the discovering of microRNA Their surprising discovery revealed an entirely new dimension to gene regulation as the microRNAs are proving to be fundamentally important for how organisms develop and function. US & World Videos 2:27 Why are there no Category 6 hurricanes? 1:13 What is Indigenous Peoples' Day? 1:38 Meghan Markle makes surprise appearance at Children's Hospital LA gala 1:51 Patriots' Jabrill Peppers arraigned on multiple charges 2:08 Hurricane Milton strengthens to Category 4 storm as it churns toward Florida