Protein profiling by reverse phase protein array (RPPA) in classical hairy cell leukemia (HCL) and HCL‐variant

Classical hairy cell leukemia (HCL‐c) and HCL variant (HCL‐v) are recognized as separate entities with HCL‐v having significantly shorter overall survival. Proteomic studies, shown to be prognostic in various forms of leukemia, have not been performed in HCL. We performed reverse phase protein array‐based protein profiling with 384 antibodies in HCL‐c (n = 12), HCL‐v (n = 4), and normal B‐cells (n = 5) samples. While HCL could be distinguished from normal based on unsupervised hierarchical clustering, overlap in protein expression patterns was seen between HCL‐c and HCL‐v, with ∼10% of the proteins being differentially expressed, suggesting potential therapeutic targets.