Fig. 3. Effect of RA on cell growth in P388D1 cells. Cells were grown in the presence or absence of 1 µM RA, and growth rate was measured by counting the viable cells in each treatment at specific time points. (), vector-transfected (receptor negative) cells without RA treatment (control); (), vector-transfected cells with RA treatment; (), M6P/IGF2R cDNA-transfected (stably) cells without RA treatment; (), M6P/IGF2R cDNA-transfected cells with RA treatment. Each point represents the mean of three separate experiments (n = 3; *, P < 0.05 versus control).