PSA from CTOS was mostly sialylated and the content of WFA reactive N-glycans (LacdiNAc) is similar to that of PSA derived from normal seminal plasma and 22Rv1 (Fig. 1), suggesting that an increase in LacdiNAc and a decrease in sialylation are not common in all prostate cancers. This evidence concerns the gene KLK3 and prostate cancer.