Activating STAT5B mutations can cause both primary hypereosinophilia and lymphocyte-variant hypereosinophilia. Issue 1 (2nd January 2023) - Umrau, Kavita; Naganuma, Ken; Gao, Qi; Dogan, Ahmet; Kizaki, Masahiro; Roshal, Mikhail; Liu, Ying; Yabe, Mariko