Nonchemotherapy treatments with reported efficacy in HCL include anti-CD20 monoclonal antibodies rituximab and obinutuzumab, anti-CD22 recombinant immunotoxin moxetumomab pasudotox (Moxe), BRAF/MEK inhibitors, BTK inhibitor ibrutinib, BCL2 inhibitor venetoclax, and allogeneic transplantation.5-13 These treatments except for BRAF inhibition may also treat HCL variant (HCLv), which is more refractory and usually lacks CD25, CD123, Anxa1, and BRAF V600E.6,14 Salvage treatments for HCL/HCLv are usually of temporary benefit. This evidence concerns the gene CD22 and hairy cell leukemia.