MUC13 and cancer: 13 of the 50 genes for clustering analysis were more highly expressed in HPV+G2 than in HPV+G1, including MUC5B, BPIFB1, PIGR, MUC13, SLC34A2, TFF3, AQP5, LTF, PROM1, GABRP, AGR3, PAX7, and TSPAN8. Among them, MUC5B and MUC13 belong to the mucin gene family, which plays oncogenic roles in various cancers (45, 46).