Inclusion Criteria:

For Cases

• Provide voluntary and written informed consent to be included in the study (for those who are not fluent in English, we will consult an interpreter who can go over the consent with patient).
• Must be willing to undergo blood collections as outlined in the protocol.
• Meeting criteria for new onset DM or worsening of existing type 2 DM after initiation of ICI:
  • New onset of diabetes mellitus any time after initiating ICI therapy based on criteria: HbA1c >6.4 % or FPG ≥126mg/dl on two occasions or OGTT >199 on two occasions or symptoms with RPG ≥200 mg/dl or initiation of any therapy for diabetes mellitus or diabetic ketoacidosis (DKA).
• Worsening of existing type 2 diabetes mellitus any time after initiating ICI therapy based on criteria: unexplained HbA1c increase by 10%, sudden RPG ≥200 mg/dl, episode of DKA, clinical need for 2nd agent or insulin for diabetes mellitus, new onset ketonuria or new onset ketonemia (elevated beta hydroxybutyrate in blood) with uncontrolled diabetes.
• Meeting criteria for hypophysitis after initiation of ICI:
  • MRI evidence of hypophysitis demonstrated by enlarged and enhancing pituitary gland and stalk or small pituitary which can be a consequence of initial pituitary swelling;
  • Biochemical evidence of hypopituitarism even in the absence of MRI findings.

For Controls

• Provide voluntary and written informed consent to be included in the study (for those who are not fluent in English, we will consult an interpreter who can go over the consent with patient).
• Must be willing to undergo blood collections as outlined in the protocol.

Exclusion Criteria:

For Cases

• Prisoners
• Not willing to voluntarily consent or if withdraw consent at any time during the course or of the study.
• Preexisting diagnosis of autoimmune (type 1) diabetes mellitus.
• Pregnant.

For Controls

• Prisoners
• Not willing to voluntarily consent or if withdraw consent at any time during the course or of the study.
• Pregnant.