COL4A5 and small cell lung carcinoma: In this work, we found that collagen IV members COL4A5 and COL4A3, integrin members ITGA1, ITGB4 and ITGA4, and linked kinase ILK all have a betweenness of more than 80 and a P value < 0.05, all of which may indicate their crucial roles in SCLC.