BTK and lymphoma: Importantly, these selective neutrophil deficits were evident not only during BTKi treatment in healthy donor neutrophils exposed to BTKi ex vivo and in neutrophils harvested from patients with lymphoma who underwent BTKi treatment, but also in neutrophils from patients with XLA who have nonfunctional BTK due to inherited BTK deficiency, and in Btk–/– mouse neutrophils.