TrkA (NTRK1) gene expression has already been described in a cohort of breast carcinomas, in which TrkA mRNA was found to be expressed in most tumours and there was a slight correlation with ER and PR [23]; however, this study only focused on the transcriptomic level, with neither HER2 nor the different molecular subtypes of breast tumours included in the analysis. This evidence concerns the gene PGR and breast neoplasm.