However, PD-1 rs2227981 variant was recognized as a risk factor in several cancers including, cervical cancer (Li et al., 2016), BC (Hua et al., 2011), gastric cancer (Savabkar et al., 2013) and thyroid cancer (Haghshenas et al., 2017). The gene discussed is PDCD1; the disease is thyroid gland carcinoma.