Methods . Animals . All of the animal experiments in this study were performed in compliance with protocols approved by the Institutional Animal Care and Use Committee (IACUC) at UCSF and Beth Israel Deaconess Medical Center. Unless otherwise specified, all of the mice had free access to food and water, and were housed under 12?h–12?h light–dark cycle, at 22?°C, and 45% humidity on average. Cul2 flox/?mice in the C57BL/6J background were generated by Applied StemCell using CRISPR...