Medulloblastoma cells (1 × 103) were plated in a 96-well culture plate with neurobasal media and treated with vehicle, 13-cis-RA (RA, 30 μM), or 9-cis-UAB30 (UAB30, 30 μM) for 72 hours. Pictures [Photometrics CoolSNAP HQ2 CCD camera (Tucson, AZ) attached to a Nikon Eclipse Ti microscope (Tokyo, Japan)] of the cells were obtained and number of neurite outgrowths per cell were counted using the image software SPOT Basic 5.2 (Diagnostic Instruments Inc., Sterling Heights, MI) and reported as mean neurite outgrowths [26 (link)].