However, only a small percentage of infected cells actually become LCLs suggesting that innate tumor-suppressor responses may restrict long-term outgrowth.16, 17 Indeed, our laboratory and others have found that the DDR is activated early after infection and the ATM/Chk2 pathway limits outgrowth through activation of a senescence-like growth arrest.18, 19, 20, 21, 22. The gene discussed is CHEK2; the disease is infection.