U.S. Reps to Gilead: Did your donation of free HIV prevention drug Truvada have strings attached?

Just weeks after Gilead pledged to donate 2.4 million bottles of its HIV drug Truvada to the U.S. government’s effort to eradicate the disease, U.S. Rep. Elijah Cummings is leading an effort to determine if the company's largesse is tied to its efforts to protect the patents on the product.