A family history of prostate cancer was associated with higher rates of PSA testing among non-Hispanic White males (IRR = 1.60, 95% CI 1.40–1.83), while there was no association among non-Hispanic Black males (IRR = 0.80, 95% CI 0.46–1.39; p-heterogeneity < 0.001). Here, KLK3 is linked to prostate cancer.