Analysis of hMLH1 methylation in tumour DNA isolated from plasma of patients with ovarian cancer before chemotherapy and at relapse showed that 25% of patients acquired hMLH1 methylation during chemotherapy and acquisition of hMLH1 methylation was independently associated with poor overall survival, potentially as a result of poor response to subsequent lines of chemotherapy (Gifford et al, 2004). Here, MLH1 is linked to ovarian carcinoma.