Dynamic changes in tumor profiling reveal intra- and inter-tumoral heterogeneity focused on an uncharacterized HER2 mutation: a case report of a young breast cancer patient oleh Dörthe Schaffrin-Nabe, Anke Josten-Nabe, Andrea Tannapfel, Waldemar Uhl, Marietta Garmer, Razelle Kurzrock, Timothy Crook, Sewanti Limaye, Stefan Schuster, Darshana Patil, Merle Schaffrin, Kefah Mokbel, Rudolf Voigtmann