TRPS1 and squamous cell carcinoma: They also analysed the staining in 141 metaplastic carcinomas, of which only 7 were negative, and 11 showed < 10% staining, i.e., the majority of metaplastic TNBCs were also TRPS1 positive [36], which points to a minor overlap with squamous carcinoma labelling described by Ai et al. [26].