U.S. Representatives Elijah Cummings and Peter Welch sent the letters to seven drugmakers.
Faced with the threat of Amazon, Walmart has been rolling out initiatives like "easy reorder" and free two-day shipping.
CEOs quitting Trump's advisory councils was a first step. Here's what they need to do now, says former Obama spokesman.
The largest railroad in the U.S. continues to cut costs, this time by laying off about 8 percent of its workforce.