Specificity of anti-phospho-TGIF1 (pTGIF1) antibody. Cell extracts from Tgif1-/- MEFs cells reconstituted with empty vector (EV), wild-type (TGIF1) or non-phosphorylated form (TGIF1.2TA) of Flag-TGIF1 were immunoblotted with anti-phospho-TGIF1 or β-Actin as a loading control. 