PGR and breast cancer: To further explore whether the correlation between LPAR1 and ZEB1 was specific to a particular subtype of breast cancer, we sub-grouped patient samples from 3 publicly available databases of primary breast tumor (GSE20685; GSE21653; GSE1456) into basal (n = 75) and non basal subtypes (n = 138) based on the ER, PR and HER2 receptor expression status.