ESR1 and breast cancer: Furthermore, we observed an increase in FAM83A protein in estrogen receptor positive (ER + ; fold change (fc):1.5 for positivity, p = 3E-11 and fc:1.7 for H-score, p = 1E-11) and progesterone receptor positive (PR + ; fc:1.6 for positivity, p = 1E-08 and fc:1.7 for H-score, p = 1E-08) BC as well as in HER2 + BC (fc:1.6 for positivity, p = 0.002 and fc:1.6 for H-score, p = 0.002) as compared with normal breasts (Fig. 1C and Additional file 1: Table S5).