In particular, correlation of MTHFR methylation levels between tumor tissue and blood was observed in the whole population (Figure 2A; n = 69; p = 0.004, r = 0.34) Moreover, correlations between blood and thymic tissue adjacent to the tumor (Figure 2B; n = 44; p = 0.007, r = 0.40) and between tumor tissue and adjacent thymic tissue (Figure 2C; n = 44; p = 0.002, r = 0.45) were observed. Here, MTHFR is linked to neoplasm.