SFRP1 and bladder transitional cell carcinoma: In transitional cell carcinoma of the bladder, several studies revealed that methylated genes such as CDH1, FHIT, LAMC2, RASSF1A, TIMP3, SFRP1, SOX9, PMF1, and RUNX3 are associated with tumor characteristics and prognosis [3, 5, 15].