MT4 and breast cancer: Cell subtypes were assigned using multiple known molecular markers: BC (Krt5+/Trp63+), SEC (Krt4+/Mt4+), TPC (Lgr5+/Wif1+), CBC (Mki67+/Top2a+), MC (Col3a1+/Mgp+), EpC (Arg1+/Ltf+), MTC (Espn+/Entpd2+), EnC (Egfl7+/Fabp4+), GN (Mpz+/Plp1+), MuC (Muc5b+/Tff2+), IC (Cd74+/C1qa+) and TMC (Gpx3+/Pax7+).