Secondly, previous studies from the PLCO trial demonstrated that only FSG screening could effectively lead to early-stage shift of CRC (9), but no significant early-stage shift was observed for PSA combined with DRE screening for prostate cancer (28), CA125 combined with TVU screening for ovarian cancer (29), and chest radiograph screening for lung cancer (27). Here, KLK3 is linked to prostate carcinoma.