NIH3T3 cell lines expressing NRASD12 or nonpalmitoylated NRASD12 result in phenotypic changes in morphology and density-dependent inhibition of growth. (A) Morphology of cultured NIH3T3 cells stably expressing the proteins indicated. Equal numbers (5 × 10⁵) of NIH3T3 cells expressing vector alone, NRASD12, NRASD12^C181S, or NRASD12^C186S were plated onto 100-mm plates and were cultured for 6 days before the pictures were taken (original magnification, ×100). (B) Total numbers of viable cells per plate (means with error bars) for NIH3T3 cells expressing vector alone, NRASD12, NRASD12^C181S, or NRASD12^C186S were plotted versus time (days). NRASD12^C186S cells grew significantly slower than the vector control cells at day 4 (P = .01). NRASD12 and NRASD12^C181S cells grew significantly faster than the vector control cells at day 6 (P = .005 and P = .02, respectively).