Biochemistry

A Falcon 9 SpaceX rocket with a resupply mission to the International Space Station lifts off from pad 40 at the Cape Canaveral Air Force Station in Cape Canaveral, Fla., Thursday, July 25, 2019. (AP Photo/John Raoux)

FILE - In this Oct. 9, 2018 file photo, an embryo receives a small dose of Cas9 protein and PCSK9 sgRNA in a microscope in a laboratory in Shenzhen in southern China's Guangdong province, during work by scientist He Jiankui's team. A report released on Monday, June 3, 2019, shows that people with a DNA mutation that reduces their chance of HIV infection have heightened overall death rate, warning that genetic tinkering can produce risks. Rasmus Nielsen of the University of California, Berkeley, senior author of the paper, acknowledged that his result cannot be applied directly to the two girls in China. (AP Photo/Mark Schiefelbein)

Visitors to the Oklahoma City National Memorial walk around the "Survivor Tree," a 100-year-old American elm and symbol of hope after the deadly 1995 bombing, Friday, April 19, 2019, in Oklahoma City. Science and technology are helping Oklahoma City to sustain the DNA of the tree symbolizing hope 24 years after the deadliest act of domestic terrorism on U.S. soil. As part of an annual remembrance of the bombing, civic leaders on Friday plan to transplant a tree that was cloned from the scarred American elm that lived through the blast. They hope the younger elm will replace the "Survivor Tree" once it dies. (AP Photo/Adam Kealoha Causey)

FILE - In this Oct. 8, 2002, file photo, Sydney Brenner, a professor in the Molecular Sciences Institute in Berkeley, Calif., gestures during a press conference in Munich, Germany. Brenner, a Nobel Prize-winning biologist who helped decipher the genetic code and whose research on a roundworm laid the groundwork for decades of human disease research, has died. The Salk Institute for Biological Studies in California said Brenner died Friday, April 5, 2019 in Singapore. He was 92. (AP Photo/Jan Pitman, File)

This Tuesday, Feb. 12, 2019 photo shows male mosquitos at the the Vosshall Laboratory at Rockefeller University in New York. In 2018, researchers at the lab published a much-improved description of the DNA code for a particularly dangerous species of mosquito: Aedes aegypti, notorious for spreading Zika, dengue and yellow fever. (AP Photo/Mary Altaffer)

A scientist at the NY Genome Center in New York demonstrates equipment used in single-cell RNA analysis on Wednesday, Sept. 26, 2018. Until recently, trying to study key traits of cells from people and other animals often meant analyzing bulk samples of tissue, producing an average of results from many cell types. But scientists have developed techniques that let them directly study the DNA codes, and its chemical cousin RNA, the activity of genes and other traits of individual cells. (AP Photo/Malcolm Ritter)

FILE - In this Wednesday, June 17, 2015 file photo, U.S. Nobel laureate biologist James Watson visits the Russian Academy of Sciences in Moscow, Russia. Watson, who lost his job in 2007 for expressing racist views, was stripped of several honorary titles on Friday, Jan. 11, 2019. (AP Photo/Ivan Sekretarev)

In this Nov. 28, 2018, photo, He Jiankui, a Chinese researcher, speaks during the Human Genome Editing Conference in Hong Kong. He made his first public comments about his claim to have helped make the world's first gene-edited babies. The uproar over the unproven report of gene-edited births in China has researchers elsewhere worried about a backlash. (AP Photo/Kin Cheung)

He Jiankui, a Chinese researcher, center, speaks during the Human Genome Editing Conference in Hong Kong, Wednesday, Nov. 28, 2018. He made his first public comments about his claim to have helped make the world's first gene-edited babies. (AP Photo/Kin Cheung)

In this Oct. 10, 2018 photo, He Jiankui is reflected in a glass panel as he works at a computer at a laboratory in Shenzhen in southern China's Guangdong province. Chinese scientist He claims he helped make world's first genetically edited babies: twin girls whose DNA he said he altered. He revealed it Monday, Nov. 26, in Hong Kong to one of the organizers of an international conference on gene editing. (AP Photo/Mark Schiefelbein)