In addition, Most of these SPTB mutations are nonsense (32/66) and frameshift (20/73) mutations, which can be considered as null mutations and cause haploinsufficiency of SPTB and ß-spectrin deficiency in HS patients, and, interestingly, most of the nonsense mutations are mainly distributed in repeats 3–15 of erythroid-spectrin protein (Figure 3). The gene discussed is SPTB; the disease is histiocytic sarcoma.