In the last sentence of the paragraph headed “aGVHD” on page 1024 in the 8 May 2018 issue, the comparison of risk of grade 3 to 4 acute graft-versus-host disease in recipients of parous female sibling donor grafts and recipients of male unrelated-donor (URD) grafts was misstated. The sentence should read, “Recipients of male URD grafts may also have experienced a higher risk of grade 3 to 4 aGVHD as compared with recipients of parous female sibling donor grafts, but this finding did not reach statistical significance given our conservative P value cutoff (RR = 1.27, P = .016) (Table 4).” The error has been corrected in the original article.