Researchers have identified specific cell types that appear to be the main targets of SARS-CoV-2, the virus that causes COVID-19. Using existing data on the RNA found in different types of cells, researchers were able to identify cells that expressed ACE2 and TMPRSS2, two proteins that assist coronavirus to enter human cells. Cells in the lungs, nasal passage and intestines appear to be the main targets for SARS-CoV-2.