PTK2 and hydrops fetalis: Results showed that total protein levels of FAK and Src were the same between NF and HF (Fig. 2A), the relative levels of activating froms p-FAK-Tyr407 and p-Src-Tyr416 were significantly up-regulated by ~3-fold (Fig. 2B,C), while the deactivating form p-Src-Tyr529 was down-regulated by ~60% (Fig. 2C) in HF, indicating the activation of both FAK and Src in HF, which coincides with in vivo data in Fig. 1.