Heterogeneous methylation as determined in the CGI of GREM1 in RCC (11) may lead to varying statistical associations with clinicopathological parameters; thus, our previous findings of GATA5 CGI methylation as a potential prognosticator for RCC would be strengthened if another GATA5 methylation locus could be identified to demonstrate association with an unfavorable prognosis. The gene discussed is GREM1; the disease is renal cell carcinoma.