SummaryBackground: Ultraviolet radiation (UVR) is known to induce the activation of stressinflammation signal transduction pathways, and to induce the activity of many proteases in skin cells. It is unknown whether the activation of proteases such as furin is related to changes in the phosphorylation status of p38MAPK. Methods: The effect of UVR on immortalized keratinocyte (HaCaT) and squamous cell carcinoma (Colo16) cells was investigated with respect to cell survival, phosphorylation of p38MAPK, and the proprotein convertase, furin. The cells were exposed to either a low or a high dose of UVA and/or UVB and the viability was monitored over 48 h, along with changes in the intracellular expression of p38MAPK and furin. Results: Low-dose UVA (2 kJ/m 2 ) and/or UVB (0.2 kJ/m 2 ) radiation had no effect on cell