CYP11A1 and infection: Furthermore, CYP11A1-overexpression could no longer decrease CYP19A1 once infected by H. pyloriWT, while CYP11A1-knockdown could still up-regulate CYP19A1 in GC cell with H. pyloriWT infection (Figure 4B, 4D, S4A and s4C), indicating H. pyloriWT may exert an indirect impact on CYP19A1 expression via CYP11A1.