CD33 and primary myelofibrosis: Among day +100 post-HCT factors, RBC transfusion dependence (HR 9.02, 95%CI 4.0–20.35, p < 0.001), platelet transfusion dependence (HR 8.17, 95% CI 3.83–17.37, p < 0.001), 100% donor chimerism in CD33 + cells (HR 0.21, 95% CI 0.07–0.62, p = 0.004), unfavorable molecular status (HR 4.41, 95% CI 1.87–10.39, p < 0.001), normal spleen size at day +100 (HR 0.42, 95% CI 0.19–0.94, p = 0.035), grade ≥ 2 of bone marrow fibrosis (vs. grade ≤ 1; HR 2.7, 95% CI 1.1–6.93, p = 0.031) and poor graft function (HR 2.6, 95% CI 1.22–5.53, p = 0.013) were statistically significantly associated with RFS.