Comment on ‘Context, not class, may be the key signal in systemic JAK inhibitor exposure in MF/SS’: reply from authors

The effects of systemic JAKis exposure in MF/SS appear context dependent and should not be interpreted as a homogeneous entity. Although disease worsening was observed in several patients initially diagnosed with presumed inflammatory dermatoses, causality cannot necessarily be inferred and may reflect, among other factors, underlying MF/SS biology, referral bias, or concurrent immunosuppressive influences. In post-transplant MF/SS patients receiving JAKis for graft-versus-host disease, MF/SS progression may reflect impaired immune surveillance or other disease-related factors rather than a direct effect of JAKis. These findings underscore the complexity of interpreting JAKi exposure in MF/SS and highlight the need for prospective studies to better define risks across clinical settings.