PMEL and breast cancer: [45] Further evidence for the involvement of the immune system is the augmentation of MHC class I expression, concurrent with increased PD‐L1 expression on mammary tumor cells.[45a] Moreover, in a mammary carcinoma model, it has also been demonstrated that IRIN can induce Treg depletion, in addition to the potential to synergize with anti‐PD‐L1.[45a] Further, a subcutaneous MC38/gp100 colon cancer model was used to demonstrate that the antitumor efficacy of an IRIN‐delivering liposome can be enhanced by ICI antibodies.[45b]