Intriguingly, we found a remarkable correlation between AIF-1 expression and the expression of HSPA1L, PRRC2A, C2, MICB, SLC44A4, AMSH5, VWA7, C4A, LTA, and NELFE in pan-cancer analysis, which also suggested that they have a certain relationship in the carcinogenic mechanism. The gene discussed is C4A; the disease is cancer.