We used shRNA to reduce the expression of LDHC in the HLA-A*0201 positive HCC1500 breast cancer cell line, resulting in A2 + /LDHC low cells with silenced LDHC expression (A2 + /low), in addition to the parental A2 + /LDHC high cells with endogenous high expression of LDHC (A2 + /high). The gene discussed is LDHC; the disease is breast cancer.