Our results showed that MMP-2 and migration/invasion of all 4 lung cancer cell lines i.e., A549, H1299, CL1-0 and CL1-5 were increased by knockdown of PP4R2, PP4C or PATZ1 but not PP4R1 (Supplementary Figure S5 and S6). Here, PPP4R1 is linked to lung cancer.