Their inactivation could contribute to tumor formation of PCC and we therefore used the combined bisulfite restriction analysis (COBRA) methylation analysis to study the promoter methylation status of the RASSF members RASSF2, RASSF3, RASSF4, RASSF5A, RASSF5C, RASSF6, RASSF7, RASSF8, RASSF9, and RASSF10. This evidence concerns the gene RASSF4 and neoplasm.