PDCD1 and endocrine system disorder: The blockade of immune checkpoints has been shown to affect the balance between autoimmunity and immune tolerance, potentially resulting in a range of immune-mediated adverse reactions, including fatigue, rashes, dermatological disorders, gastrointestinal events, endocrinopathies, and diarrhea.[32,33] The toxicity associated with anti-PD-1/PD-L1 monoclonal antibodies (mAb) is relatively uncommon and generally less severe than that of anti-CTLA-4 mAb.