CSF3 and chronic graft versus host disease: In the multivariate analysis, administration of G‐CSF was significantly associated with a higher risk of overall chronic GVHD following BMT (HR 1.20, 95% CI 1.00–1.43, p = .040) and CBT (HR 1.42, 95% CI 1.10–1.84, p = .007) (Table S1).