CYP2B6*32 (c.1219G>A, p.A407T) – Normal function: CYP2B6*32 is assigned normal function. A study evaluating efavirenz content in hair samples among patients with HIV taking efavirenz for more than three months found CYP2B6*32 did not impact long term efavirenz content (26655325) compared to the *1 reference. Although one in vitro study using a cDNA expression system found that CYP2B6*32 demonstrated increased enzyme activity compared to the *1 reference (30201214), the experts did not find these results convincing. Therefore, consensus among experts was normal function based on limited evidence.