Results: MR analysis suggested a negative causal relationship between PCSK9 inhibitors and both breast and lung cancers (95%CIBreast cancer 0.81~0.99, p = 2.25 × 10−2; 95%CILung cancer 0.65~0.94, p = 2.55 × 10−3). Here, PCSK9 is linked to lung cancer.