ANK1 and histiocytic sarcoma: The analysis of all HS-associated mutations (including 144 from previous reports and 14 from this study) in Chinese patients showed that ANK1 or SPTB was the major causative gene of HS cases, which is consistent with previous reports (Delaunay, 2007; Park et al., 2016; Wang et al., 2018; Qin et al., 2020), but only 5–10% of HS cases in Japan or Brazil were caused by ANK1 mutations, implying that the geographical distribution of ANK1 gene mutations is different.