Adding AAT into patient sera from day +7 significantly improved re-epithelialization rates in the GVHD-free group, but not in the aGVHD group (ΔRWD 2.95% and −0.7%, respectively); in contrast, patient sera from day +28 exhibited a reciprocal trend (ΔRWD 0.19% and 1.44%, respectively) (Figure 4A). Here, SERPINA1 is linked to graft versus host disease.