In terms of stringent objective response criteria modeled after the clinical setting, six out of eight PDXs scored the highest ORM of maintained complete response (MCR), including all three BCP‐ALLs (ALL‐2, ALL‐7, ALL‐19), two MLLr‐ALLs (ALL‐3 and MLL‐1), and one Ph+‐ALL (ALL‐55) with the other two PDXs (one MLLr‐ALL, MLL‐5, and one Ph+‐ALL, ALL‐4) scoring progressive disease 2 (PD2; Table 1). Here, KMT2A is linked to acute lymphoblastic leukemia.