Analysis of PSA expression in 33 TCGA cancer types revealed low levels in adrenocortical carcinoma (0.3 GPM), colon adenocarcinoma (0.2 GPM), kidney chromophobe carcinoma (8.1 GPM), and rectum adenocarcinoma (0.3 GPM). This evidence concerns the gene KLK3 and colon adenocarcinoma.