For the HLA class II subtypes, we demonstrated that HLA-DRA (p=0.046), HLA-DRB1 (p=0.010), HLA-DRB4 (p=0.017), HLA-DRB6 (p=0.004), HLA-DPB2 (p=0.0005), and HLA-DQB1 (p=0.007) of tumor tissues were lower than that of normal tissues in SCLC patients, while HLA-DPA1, HLA-DPA2, HLA-DPB1, HLA-DQA1, and HLA-DQB2 were all not (p>0.05) (online supplemental figure 3B, C). Here, HLA-DRB1 is linked to small cell lung carcinoma.