To evaluate the effects of cell-derived IFN-γ on the viability of cancer cells, C3H10T1/2, C3H10T1/2/HSVtk, C3H10T1/2/IFN-γ, or C3H10T1/2/HSVtk/IFN-γ cells were cultured for 48 h, and the supernatants were collected as conditioned medium. The gene discussed is IFNG; the disease is cancer.