Among nine major cancer forms, low levels of HDL cholesterol and apolipoprotein A1 were associated with increased risk of hematological cancer, breast cancer, and respiratory cancer, but not with gynecological cancer, urological cancer, gastrointestinal cancer, prostate cancer, malignant melanoma, or other cancer in the Copenhagen General Population Study (Figs. 2 and 3 and Figures S1 and S2). The gene discussed is APOA1; the disease is breast cancer.