One important change within those categories affect splenic B-cell lymphomas and leukaemias, within which the term “splenic B-cell lymphoma/leukaemia with prominent nucleoli” replaces the provisional category of “hairy cell leukaemia (HCL) variant (v)” of WHO-HAEM4R and also absorbs cases of “CD5-negative B-cell prolymphocytic leukaemia”, among others. The gene discussed is CD5; the disease is hairy cell leukemia.