on outcomes. A lower risk of late relapse was seen with several cGVHD specific variables (P\0.0001), i.e., mild, moderate or severe cGVHD; de novo or progressive cGVHD; or involvement of any organ with cGVHD. These results demonstrate a protective effect of cGVHD on late relapse only in CML. In addition, presence of cGVHD by 1 year after HCT was associated with a higher risk of TRM and inferior OS in all patients (CML, AML, ALL, MDS). Since the protective effect of cGVHD on late relapse was seen only in CML patients, more aggressive measures to control cGVHD may be beneficial especially in AML, ALL and MDS patients after high intensity conditioning regimen.