After transfecting the human IL-22 cDNA into lung cancer A549 and PG cells, the overexpression of IL-22 inhibited the chemotherapy-mediated apoptosis of A549 and PG cells through the activation of STAT3 and its downstream antiapoptotic proteins, such as Bcl-2 and Bcl-xl [16]. The gene discussed is BCL2; the disease is lung carcinoma.