Analysis of SAMHD1 expression in T-ALL cells versus B-ALL cells included in PRoXe, a public repository of patient-derived leukemia cells (https://www.proxe.org/), revealed a similar pattern, with most T-ALL cells lacking detectable SAMHD1 expression, and the majority of B-ALL cells expressing SAMHD1; dCK was expressed at similar levels in T-ALL cells and B-ALL cells (Supplemental Figure 1G). Here, SAMHD1 is linked to leukemia.