To identify the immune peptides in SCLC tumour cells that can be processed and presented by HLA-I, we performed LC–MS/MS analysis on 11 SCLC cell lines, representing the heterogeneity of SCLC subtypes. Ten of the cell lines were confirmed positive for HLA-I, and one was HLA-I-deficient. To analyse cell surface antigens on the HLA-I-deficient cells, PBMCs isolated from healthy blood donors were treated with DMS53 cell lysate and matured into DCs to present the tumour cell antigens.