API5 role in cell proliferation and colony formation of HEK293, CaSki, and HeLa cell lines. (A) API5 protein expression was analyzed by western blot. (B) Proliferation assay: 2 × 104 cells were plated in 24 well plates and cultured for additional 6 days. Cells were collected by trypsinization at the indicated times, and live cells were counted after trypan blue staining under a haemocytometer. (C) Colony formation: 500 cells were plated in 6 well plates and cultured for 2 weeks and formed colonies were stained with crystal violet. Data depicted as mean + s.e.m. from one representative experiment performed in triplicate.