Albeit no correlation between CD123 expression in primary BPDCN and in vitro cell lysis could be demonstrated (not shown), the specificity was confirmed by the lack of cytotoxic activity of UCART123 against CD123-negative Daudi cells and a trend towards increasing degranulation, cytotoxic activity and IFNγ release by CART cells against AML cell lines with higher CD123 levels (Supplementary Fig. 3). Here, IL3RA is linked to acute myeloid leukemia.