Firstly, cancer screening history was derived from self-report, however a meta-analysis of validation studies on self-reported cancer screening use in the USA found that self-reported versus documented history of screening had reasonably high sensitivity (0.78 for FOBT, 0.95 for mammography, 0.71 for PSA) and specificity (0.90 for FOBT, 0.61 for mammography, 0.73 for PSA) [57]. The gene discussed is KLK3; the disease is cancer.