RET and neoplasm: After confirming the stability of the SQ-siRNA conjugate in serum and its lack of toxicity in cells (Figure 4B), in vitro and in vivo transfection experiments confirmed the efficient knockdown of the RET/PTC1 mRNA in the presence of commercially available cationic lipids (~80%) (Figure 4C) and the ability of SQ-siRNA nanoparticles for inhibiting the tumour growth (~70%) in model mice xenografted RET/PTC1 (Figure 4D,E).