In line with this, in H1N1/WSN and H5N3 virus infection an elevated level of IFIT1 was associated with increased expression of anti-apoptotic genes XIAP associated factor 1 (XAF1) in both viruses and TNF receptor-associated factor 1 (TRAF1) in H5N3 virus infection  (Fig. 5a) in response to early cell death [48]. Here, XAF1 is linked to viral infectious disease.