Scoring of DA and RA FLSs immunofluorescence. DA FLSs cultured on glass slides in the presence or absence of calcitriol (CALC) were scored for actin filament characteristics, cell shape, lamellipodia formation and location and p-FAK localization (see Materials and Methods for details). Calcitriol treatment significantly reduced the number of cells with thick actin filaments (A, E), the number of elongated cells (B, F), the formation of polarized lamellipodia (C, G) and the colocalization of p-FAK with lamellipodia (D, H) (*P < 0.05, t test; data shown as mean ± SD; DA, n = 4 per treatment group [50 nmol/L calcitriol]; RA, n = 5 per treatment group [1 μmol/L calcitriol]).