TNF and cancer: In contrast, IFN-γ/TNF did not induce SA-β-gal in the RT2.CRISPR-Cdkn2a-cancer cells, and the cells restarted exponentially growing after IFN-γ/TNF withdrawal, showing that RT2.CRISPR-Cdkn2a-cancer cells were resistant to CIS (Fig. 3c).