To further elucidate the effect of anxiety on PSA testing Consedine et al., in a small study of 533 American men, aged 45 to 70 years, investigated the effect of three components of anxiety i.e. dispositional anxiety, prostate cancer worry, and screening fear on frequency of PSA testing (and digital rectal exams (DRE))[18]. This evidence concerns the gene KLK3 and Familial prostate cancer.