Future incidence of chronic GVHD. Future incidence of cGVHD under base-case assumption considering most current available estimates (A), increased PTCy-based prophylaxis use (at 35% of matched related donor (MRD), 50% MUD, and 75% MMUD) (B), increased proportion of haploidentical donor (40% of HCT) with PTCy use (C), and increase in both haplo-HCT (40% of HCT) and marked PTCy use across other approaches (PTCy as 75% of MRD, MUD, and MMUD cases) (D). Bars in each figure represent the predicted yearly incidence of cGVHD under the appropriate assumptions, with the left-hand axis applying to these predictions; the lines in each figure represent the cumulative predicted incidence, with the values at each year representing the sum of all years up to the listed year. Modeling assumptions and variation explored are listed in the supplemental Methods. The projected number of cGVHD cases per donor type includes the following: (A) MRD, 11 688; MUD, 25 602; MMUD, 3760; haplo, 8074; UCB, 1258. (B) MRD, 10 790; MUD, 21 116; MMUD, 3627; haplo, 8074; UCB, 1258. (C) MRD, 11 688; MUD, 18 620; MMUD, 2686; haplo, 14 043; UCB, 315. (D) MRD, 8078; MUD, 12 950; MMUD, 2642; haplo, 14 043; UCB, 315. MMUD, mismatched unrelated donor; UCB, umbilical cord blood.