Fig. 4. Ratio of the relative fluorescence intensities (nucleus/cytosol; mean and s.d.) of the Ca²⁺ indicators at maximal (URC) or final (CRF values of the time-dependent response (see Fig. 6) in HaCaT keratinocytes (4A) and human malignant melanocytes (4B) after stimulation with URC (U, filled bars) and CRF (C, unfilled bars) and in neonatal keratinocytes (K, unfilled) and normal melanocytes (NM, filled) after stimulation with CRF (4C). *Statistically significant differences (P<0.05, unpaired t-test) between the ratios after stimulation with URC and with CRF; +, statistically significant differences (P<0.05, unpaired t-test) between the ratios in keratinocytes and normal melanocytes. Number of cells recorded (n) is shown in the respective columns.