Accordingly, there is intense interest to develop isoform‐selective HDACi's, notably of HDAC1 and HDAC6 (and HDAC8) (Deng et al. 2023; Ho et al. 2020) HDAC1 is overexpressed in a wide range of solid tumors as well as in several leukemias and lymphomas, including acute lymphoblastic leukemia (ALL), CLL and AML (Deng et al. 2023). Here, HDAC6 is linked to B-cell chronic lymphocytic leukemia.