Therefore, ways to augment free cholesterol accumulation such as inhibition of cholesterol esterase (ACAT1) or sustaining LDLR activity by blocking tumour cell-derived proprotein convertase subtilisin/kexin type 9 (PCSK9), proved to be effective in potentiating CD8+ T cell activity in tumours38,39,63. Here, PCSK9 is linked to neoplasm.