PDCD1 and small cell lung carcinoma: Additionally, Point biserial correlation analysis between PNI and disease control rate (DCR) showed that PNI status was positively correlated with DCR in SCLC patients receiving PD-L1/PD-1 inhibitors or combined with chemotherapy (r = 0.351, p < 0.001; r = 0.285, p < 0.001, respectively).