Non-cytotoxic peptide with immunosuppressive and insulinotropic effects (PubMed:31639404). Induces an increased production of the anti-inflammatory cytokine IL-10 and inhibits production of the pro-inflammatory cytokines TNF-alpha and IL-1beta, when incubated with mouse peritoneal cells (PubMed:31639404). Does not display growth-inhibitory activity against the Gram-positive S.epidermidis and Gram-negative E.coli bacteria and against the opportunistic yeast pathogen C.parapsilosis (MIC>128 uM) (PubMed:28951157). In addition, it lacks cytotoxic activity against mouse erythrocytes (LC(50)>500 uM) and A549 human non-small cell lung adenocarcinoma cells (LC(50)>100 uM) (PubMed:28951157). Moderately stimulates insulin release from rat clonal beta-cells and mouse pancreatic islets (PubMed:31639404). Non-cytotoxic peptide with immunosuppressive but without insulinotropic effects (PubMed:31639404). Inhibits production of the pro-inflammatory cytokines TNF-alpha, but has no effect on IL-10 and IL-1beta production, when incubated with mouse peritoneal cells (PubMed:31639404). Has no activity of stimulation of insulin release (PubMed:31639404). Expressed by the skin glands. May represent a template for the development of an agent for use in anti-inflammatory and type 2 diabetes therapies. RP-33 is present in skin secretions in higher concentration than RP-27 (PubMed:28951157). RP-33 may be a precursor of RP-27 that is activated in the skin in response to an appropriate stimulus (Probable).