Similarly, our studies on the human proteome reveal an unappreciated complexity of self-peptides capable of stabilizing HLA-E and modulating NK cell responses, including proteins associated with cancer metastasis and apoptosis regulation59–61, and future studies may investigate if these peptides provide a more extensive monitor of cellular states through surveillance by NK and potentially T cells of cellular processes beyond MHC class I expression. Here, HLA-E is linked to cancer.