Among the proteins elevated in plasma of SCLC-bearing mice were ALDOA, CAP1, FBLN2, FGL1, GSR, KRIT1, LTBP4, PDIA3, PKP3, PSMA5, S100A8, SH3BGL3, TPM4 and YWHAE, which were also identified as elevated in case plasmas (AUC ≥ 0.60) in this study, thus providing additional validation of the association between these circulating protein features and SCLC development. This evidence concerns the gene KRIT1 and small cell lung carcinoma.