The wide range of hepatotoxicity rates among patients receiving cART may be related to different study designs and populations (age, gender, races, and body weight), prevalence of HBV or HCV coinfection, definitions of hepatotoxicity used, follow-up duration, CD4 counts (particularly in pregnant patients with CD4 >250 cell/μl receiving nevirapine for the prevention of mother-to-children transmission) [43], and antiretroviral regimens initiated. The gene discussed is CD4; the disease is coinfection.