CPSF4 and lung cancer: To further confirm the role of CPSF4 in regulating lung cancer cell growth via the PI3K/AKT and MAPK signaling pathways, H1299 cells were transfected with an expression vector encoding CPSF4 (pcDNA3.1-CPSF4) or a control vector lacking CPSF4 (pcDNA3.1).