ITGB2 and small cell lung carcinoma: Interestingly, we did not detect significant differences in the expression levels of these markers between the clusters C1 and C2 of SCLC patients (Figure 4A-B), nor a significant linear correlation between the expression of ITGB2 and ASCL1 (R2 = 0.43), NEUROD1 (R2 = 0.11), POU2F3 (R2 = 0.13) and YAP1 (R2 = 0.00) by linear regression analysis (Figure 4C).