JAK2 and Thrombocytopenia: Thrombocytopaenia, anaemia and neutropenia, resulting from inhibition of the JAK2‐signalling thrombopoietin, erythropoietin and G‐CSF/GM‐CSF respectively, have been described,34, 35, 36 which promotes the notion that selectivity against JAK2 may be desirable to improve safety.