The proximal region and tyrosine residue 338 of IL-2Rβ A region are crucial for lineage conversion. (A) Illustration of deletion chimeric receptors. IL-2Rβ A region was divided into 2 sub-regions (a.a. 313-353 [proximal] and a.a. 354-382 [distal]). (B) The chimeric receptors shown in panel A were retrovirally introduced into CLPs. The lineage conversion ability of each chimeric receptor was examined by myeloid colony forming ability in methylcellulose culture in the presence of IL-3 and GM-CSF. (C) Diagram of tyrosine-to-phenylalanine mutants. The individual tyrosine (Y) residues within IL-2Rβ A region were mutated into phenylalanine (F). (D) Lineage conversion ability was assessed with the methylcellulose culture as described for panel B. (B,D) Error bars represent standard deviation from triplicate samples.