Biomarkers predictive of anti-immune checkpoint response

A method of treating a cancer in a subject likely to be responsive to an immune checkpoint therapy, wherein the immune checkpoint therapy comprises at least one antibody selected from the group consisting of anti-PD-1 antibodies, anti-CTLA-4 antibodies, and combinations thereof, the method comprising

• i) selecting the subject, the subject having been identified according to:
• a) obtaining or providing a subject sample from a patient having cancer;
• b) measuring the amount or activity of ARID2 in the subject sample;
• and
• c) comparing the amount or activity of ARID2 in a control sample,
• wherein the absence of or a significantly decreased amount or activity of ARID2 in the subject sample and/or the presence of or a significantly increased amount or activity of ARID2 having a loss of function mutation resulting from a missesnse mutation, nonsense mutation, splice site mutation, or frame shift deletion mutation in the subject sample, relative to the control sample identified the cancer as being more likely to be responsive to the immune checkpoint therapy;
• and
• ii) administering the immune checkpoint therapy to the selected subject.