However, rather surprisingly, of the ‘top 14’ most frequently reported genes that are hypermethylated in human cancers (Cheung et al, 2009), all of which were included in our array analysis, only RASSF1A, APC and ESR1 were methylated in the majority of YSTs and almost none were methylated in germinomas. Here, RASSF1 is linked to germinoma.