CASP4 and non-small cell lung carcinoma: Based on these analyses, among patients who presented with high levels of caspase-4 (Fig. 3b, red bar), those who were negative for PD-L1 represented 88.1% (Fig. 3c) compared to PD-L1 positive patients (Fig. 3c, 11.9%), implying a further stratification of NSCLC patients.