Additionally, 12 out of 18 SAMHD1-mutated CLL patients showed abnormalities involving the SAMHD1 locus, located on chromosome 20, including copy-neutral loss of heterozygosity (cnLOH), mosaic cnLOH, or even complete loss of the second allele [15]. Here, SAMHD1 is linked to B-cell chronic lymphocytic leukemia.