GADD45A and lung adenoma: Since GADD45A, a direct target of PtpA, plays an important role in regulating cell proliferation and migration25, 26, we thus performed CCK-8 and cell migration assays to examine the regulatory roles of PtpA on proliferation and migration of the human lung adenoma A549 cells infected with WT BCG, BCG ΔPtpA, BCG (ΔPtpA + PtpA), BCG (ΔPtpA + D126A), or BCG (ΔPtpA + PtpA Δ1-20).