CD45, the predominant transmembrane tyrosine phosphatase in leukocytes, is required for the efficient induction of T cell receptor signaling and activation. Various studies have demonstrated that viruses can interfere with the functions of CD45 and that patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are immune-suppressed. We recently reported that the CD45-intracellular signals in peripheral blood mononuclear cells (PBMCs) of triple negative breast cancer (TNBC) patients are inhibited. We also reported that C24D, an immune modulating therapeutic peptide, binds to CD45 on immune-suppressed cells and resets the functionality of the immune system via the CD45 signaling pathway. Given the similarity between the role of CD45 in viral immune suppression, reported by others, and our findings on TNBC, we hypothesized that the C24D peptide may have a similar “immune-resetting” effect. We tested this hypothesis by comparing the CD45 intracellular signaling in PBMC