CXCR4 and Thrombocytopenia: The main toxicity findings in HuCXCR4KI dosed with ADCs 711 and 713 at the non-tolerated 10 mg/kg/dose were in the haematopoietic compartment: thrombocytopenia, erythropenia and leucopenia, due to anti-CXCR4 ADC-related toxicity in bone marrow, spleen and thymus (Fig. 6b–d), whereas no severe toxicity was observed in other CXCR4+ adult tissues6–8,53.