JUNB and small cell lung carcinoma: A very high discriminative ability was observed for both JUNB [c‐statistic = 0.949 (95% CI: 0.882–1)] and CXCR4 [c‐statistic = 0.903 (95% CI: 0.81–0.996)] protein exosomal overexpression in SCLC patients compared to HDs, as shown in Fig. 4B,D.