STAT3 and pure red-cell aplasia: The lower VAFs of STAT3 mutations in LGLL-associated PRCA than those LGLL without PRCA, which was consistent with a previous report [32], and frequent clonal T cells negative for STAT3 mutations in other subtypes of PRCA imply that STAT3-mutated T cells might not directly affect impaired erythropoiesis of T cell-mediated PRCA.