GDF15 and neoplasm: Hypermethylation was associated with advanced tumor stage for ABCC6 (P = 0.050), BRCA1 (P = 0.032), CDH1 (P = 0.004), GDF15 (P = 0.005), HSPA2 (P = 0.000), RASSF1A (P = 0.003), TSHB1 (P = 0.018), and TMEFF2 (P = 0.002).