CD34 and graft versus host disease: In contrast, Fernandez-Sojo et al. compared 32 patients who underwent matched unrelated donor (MUD)-HSCT using cryopreserved PBSC with 32 patients who underwent MUD-HSCT using fresh grafts during the COVID-19 pandemic: despite a lower dose of CD34+ viable cells infused, no differences were observed regarding engraftment, GVHD, TRM, PFS, and OS between two cohorts.