CTSL and neoplasm: Nevertheless, 15 genes (EYA4, KCNK4, ZNF215, DAPK1, TMEFF2, SEPT5, SOX17, PENK, CTSL, BMP4, HTR1B, COL1A2, FRZB, SMARCB1, and CCNA1) were each methylated in >20% of the three subtypes and did not show significant differences in methylation frequency between tumour subtypes.