“ It really misleading claim really bad science. ” Finding peculiar features Andersen ’ group next set determine whether virus could accidentally released lab.That ’ real possibility researchers many places working coronaviruses potential infect humans , says. “ Stuff comes lab sometimes , almost always accidentally , ” says.A couple unexpected features virus caught researchers ’ eyes , Andersen says.In particular , gene encoding coronavirus ’ spike protein 12 extra RNA building blocks , nucleotides , stuck it.This spike protein protrudes virus ’ surface allows virus latch onto enter human cells.That insertion RNA building blocks adds four amino acids spike protein , creates site protein enzyme called furin cut.Furin made human cells , cleaves proteins spots particular combination amino acids found , like one created insertion .