Similar to the findings for neutrophil engraftment, reconstitution of platelets did not reveal differential effects in primary vs secondary MF, with JAK2, CALR and MPL driver mutations or different prognostic risk group, but splenomegaly significantly prolonged platelet engraftment (p=0.002, HR: 0.930, Supplementary Table 2). This evidence concerns the gene MPL and Splenomegaly.