Stable silence of CypA in M139 cells results in reduced cell proliferation. Stable cell lines expressing shCypA (CypA silence, M139-shCypA) or control shRNA (empty vector, M139-shV) were generated. CypA silence was confirmed by (A) real-time PCR using β-actin as an internal control; and (B) Western blot. (C) Stable CypA silence led to reduced cell proliferation in vitro. Cell proliferation rates are shown as the fold increase, normalized to the rate at the time of seeding. (D) CsA treatment inhibits cell proliferation.