Normal and sickle shaped red blood cells 

In this June, 27, 2015, file photo, Bree Newsome of Charlotte, N.C., climbs a flagpole to remove the Confederate battle flag at a Confederate monument in front of the Statehouse in Columbia, S.C. After nine black parishioners were slain at a Charleston church, South Carolina did what many thought would never happen: It moved the Confederate flag off Statehouse grounds. But for the most part, Charleston and other areas of the South remain unchanged. (AP Photo/Bruce Smith, File) 

In this May 14, 2014 file photo, an AT&T logo is seen on a store in Dedham, Mass. In a big win for the Obama administration, a federal appeals court on Tuesday upheld the government's "net neutrality" rules that require internet providers to treat all web traffic equally. (AP Photo/Steven Senne, File) 

In this photo taken May 18, 2016, Malia Obama uses her phone at the swing and play set on the south grounds of the White House outside of the Oval Office in Washington. President Barack Obama's daughter Malia was just 10 and longing for a promised puppy when her family moved into the White House. She's marked some of life's milestones in the past seven years, and another one comes Friday: graduation from high school. (AP Photo/Pablo Martinez Monsivais) 

Akera Price-King, 9, carries a sign saluting Muhammad Ali on the street in front of Ali's boyhood home Friday, June 10, 2016, in Louisville, Ky. Ali's funeral procession is scheduled to pass by the house later in the day. (AP Photo/Mark Humphrey) 

This June 1, 2016, photo depicts images from the Civil Rights era that are part of a new exhibit on race at the South Carolina State Museum, in Columbia, S.C. A year after the tragic shootings of nine members of a historic black church in Charleston, officials hope "Race: Are We So Different?" will inspire constructive conversation and opportunities for healing. (AP Photo/Meg Kinnard) 

Republican presidential candidate Donald Trump speaks during a news conference at the Trump National Golf Club Westchester, Tuesday, June 7, 2016, in Briarcliff Manor, N.Y. (AP Photo/Mary Altaffer)