STAT1 and small cell lung carcinoma: Our data show that there is a correlation between the levels of phosphorylated Y701-STAT1 and DNA damage resistance in SCLC cell lines (Figure 6A), suggesting that DNA damage-resistant cancer cells produce IFNs in sufficient quantity to induce higher levels of STAT1, STAT2, and IRF9 proteins but not enough to induce cytotoxic genes, compared to sensitive cancer cell lines or normal cells.