Effect of active Ral proteins on HET-SR cells growth characteristics. (a) Ral proteins expression has no significant influence on HET-SR cells proliferation.; OD595 absorption in MTT test is shown as average of three independent experiments ± SE. (b) RalB is more active than RalA in stimulation of colony formation in clonogenicity assay. Colonies were measured 6 days after seeding at low cell density (200 cells per 6-cm dish); colony size is shown in arbitrary units as average for three independent experiments ± SE. (c) Neither RalA nor RalB modulate tumorigenicity of HET-SR cells. Indicated is the size of tumors two months after injection as average for 10 animals ± SE.