BIN1 and hydrops fetalis: Overall, our work provides extensive evidence that (1) PIP2 binds to Bin1, which has been a highly controversial issue in the heart, (2) Bin1 isoforms are capable of inducing tubule formation, and (3) PIP2 depletion causes loss of TTs in the heart in a manner that mimics the TT remodeling that occurs in HF.