Unagami K, Ishida H, Furusawa M, et al. - Despite being a key immunosuppressant agent for kidney transplantation (KTx), the optimal serum trough level of tacrolimus (TAC) for good long-term results are not clear, therefore, researchers explored the link between the maintenance TAC trough level and the appearance of de novo donor-specific anti-human leukocyte antigen (HLA) antibodies (dnDSAs). Participants were 584 KTx recipients, including 164 who exhibited dnDSAs during the observation span and 420 who did not. A significantly greater number of HLA-A/B/DR mismatches, a greater probability of having preformed DSAs, and poor allograft outcome were noted in patients who developed dnDSAs. For KTx recipients whose TAC trough concentrations were kept within the narrow range of 4–6 ng/mL during the immunosuppression maintenance span, experts found no clear association between TAC trough level and dnDSA incidence in this study.