CLYBL and neutropenia: BTK inhibitors showed milder haematological toxicity in comparison to CIT; for example, severe neutropenia occurred in 26 vs. 45% with ibrutinib + rituximab vs. FCR [60], in 15 vs. 45% with ibrutinib vs. BR [59], or 10 vs. 41% with acalabrutinib vs. G-CLB [82].