NTRK1 and breast carcinoma: To confirm whether TrkA-mediated STAT3 activation can indeed promote breast cancer cell stemness, we transiently overexpressed TrkA in BT20 cells, which have relatively lower levels of activated TrkA and STAT3, with and without constitutively active STAT3 (STAT3-CA), and we performed flow cytometry to determine changes in the CD44high/CD24low population of cells.