Although splenomegaly was not observed in Trpm7fl/fl-Pf4Cre mice, we found an increased number of MKs in an expanded red pulp in the spleen and in line with the increased MK numbers, plasma thrombopoietin levels were decreased, thus further indicating deregulated megakaryopoiesis (Supplementary Fig. 4a–d). The gene discussed is THPO; the disease is Splenomegaly.