ESR1 and breast cancer: In further subgroup analysis for breast cancer with adipose stroma and non-adipose stroma, stromal LPA3 positivity showed significant association with higher histologic grade in adipose stroma group (p < 0.001), and higher histologic grade (p < 0.001), ER negativity (p < 0.001), and non-luminal A type (p = 0.001) in non-adipose stroma group (Supplementary Figure S2).