Prior data showed that THY1 (CD90) is transcriptionally repressed by IKZF1 (Ikaros) and is overexpressed in drug-resistant, IKZF1-altered BCR::ABL1 ALL.19 As we here observed that THY1 is enriched in the hybrid cluster C2 (Figure 5F), we tested if THY1 could be used as a cell surface marker for this hybrid cluster. This evidence concerns the gene ABL1 and acute lymphoblastic leukemia.