Decreased expression of PCSK9 in blood was associated with a reduced risk of rectal cancer (OR = 0.65, 95% CI: 0.45–0.95, p = 0.03), but an increased risk of pancreatic head cancer (OR = 3.11, 95% CI: 1.01–9.52, p = 0.046). The gene discussed is PCSK9; the disease is rectal cancer.