Frequently methylated genes (i.e., CDKN2A, GADD45y, FGFR2, CASP8, and PTAG) demonstrate methylation in over 50% of PAs; moderately methylated genes (i.e., TSP-1, RASSF1A, RB1, p73, MGMT, and CDH1) demonstrate methylation in 20–50% of PAs; and infrequently methylated genes (i.e., p14, DAPK1, TIMP3, p21, and p27) are methylated in less than 20% of PAs (79, 154). This evidence concerns the gene RB1 and gonorrhea.