Several immune-related targets were found to be correlated with SLFN11 in early-stage SCLC, including 16 Type I IFN signaling pathway genes and targetable immune markers PDL1 and CTLA4. SLFN11 is expressed by T-cells and monocytes and is an IFN-stimulated gene in peripheral blood mononuclear cells [36]. Here, CTLA4 is linked to small cell lung carcinoma.