PRSS3 and urinary bladder carcinoma: In a bladder cancer study conducted in New Hampshire (USA), tumor suppressor genes RASSF1A and PRSS3 were hypermethylated in bladder cancer tumors collected from 18 individuals who had toenail As levels at or above the 95th percentile compared with 318 tumors from individuals with toenail arsenic levels below the 95th percentile (Marsit et al. 2006).