The expression of COL1A2, COL3A1, COL5A2, ITGA5, and ITGB1 in SCLC, LCNEC, and typical carcinoid samples in the GSE1037 profile, as compared with normal samples, were determined using a GEO2R online analyzer (log FC>2 and adjusted P<0.05) and then compared to the data from our cohort. Here, COL1A2 is linked to carcinoid tumor.