Therefore, HIV gp120 causes at least two distinct effects upon the liver: 1) low level of background death [24] which may account for the increased liver disease in HIV mono-infected patients compared to uninfected patients, and 2) increasing TRAIL-R2 expression, and co-incident acquired sensitivity to TRAIL mediated apoptosis [14], which likely contributes to the accelerated course of co-morbid liver disease during HCV co-infection. This evidence concerns the gene ITIH4 and liver disorder.