The methylation analysis of the genes EBNA1, LMP1, RASSF1A, DAK, ITGA9, P16, WNT7A, CHFR, CYB5R2, WIF1, RIZ1, and FSTL1 [43] in Moroccan and Southern Chinese patients with NPC revealed differences in DNA methylation sensitivity and specificity among NPC populations from these different regions. The gene discussed is WIF1; the disease is nasopharyngeal carcinoma.