Ramasamy et al. reported a case of HCL with fever of unknown origin, splinter haemorrhages with vasculitis and moderate splenomegaly and cytopenia at diagnosis, suggesting infective endocarditis; however, the PB cultures and transthoracic echocardiogram were normal, and BM infiltration by CD19, CD25, CD11c, CD45 and CD103-positive lymphoid cells indicated a diagnosis of HCL [129]. This evidence concerns the gene CD19 and hairy cell leukemia.