PRDM14 expression was inversely correlated with estrogen receptor expression (ρ = −0.33, P < 0.001), a marker of breast tumor differentiation, and showed no association with progesterone receptor (ρ = 0.15, P = 0.95) or human epidermal growth factor receptor (HER)-2 expression (ρ = −0.09, P = 0.55). This evidence concerns the gene ESR1 and breast neoplasm.