P1397: CHRONICALLY REDUCED LEVELS OF THROMBOPOIETIN IMPAIR HEMATOPOIETIC STEM CELL FUNCTION AND MEGAKARYOCYTE BONE MARROW NICHE. (23rd June 2022) - Aprile, A.; Storto, M.; Malara, A.; Gulino, A.; Raggi, L.; Sighinolfi, S.; Beretta, S.; Merelli, I.; Marktel, S.; Ponzoni, M.; Tripodo, C.; Balduini, A.; et al.