Figure 4. Hsp70 expression of RF/6A cells after laser irradiation. A: RF/6A cells treated with various laser powers and followed by 18 h incubation. B: RF/6A cells treated with 700 mW laser power and followed by various incubation times. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as an internal control. Data are the mean±standard error of the mean (SEM) of three separate experiments (*p<0.05 versus control cells, Student t test).