PRF1 and infection: After 2-days, downregulation of genes required for natural killer (NK) cell activation such as mhc1, phosphoinositide-3-kinase (pik3r5), mitogen-activated protein kinase (map2k1), GTPase HRas-like (hras), fas ligand (faslg), prf1 or caspase 3 (casp3b), suggested the inhibition of apoptosis and lysing of infected cells therefore favoring infection (Figure S1, A in File S1).