Figure 3: siRNA efficiency to knock down Sos1 gene in MDAMB- 231 cells. (A) Western Blot showing the effect of siRNA treatment at different time intervals on Sos1 protein expression in the MDAMB-231 breast cancer cell line. CTRL represents the untreated control sample. β-Actin expression was utilized as a housekeeping gene for loading calibration. (B) Quantification of the efficiency of Sos1 knockdown at the protein level using western blot and an image analysis software “the Image J software”. Sos1 expression is normalized with the corresponding level of β-actin and represented as a percentage of the Sos1 expression in the control sample.