Jaing T-H, Wang Y-L. Epstein-Barr virus reactivation and post-transplant lymphoproliferative disease risk deserve a place in the JAK inhibitor toxicity profile. Comment on: “Janus kinase inhibitors as an evolving treatment for lymphomas and immune-mediated complications”. Haematologica; https://doi.org/10.3324/haematol.2026.301889 [Early view].