CAMKK2 and infection: CTRP9 knockdown markedly suppressed the infection-induced upregulation of AdipoR1, CaM, CaMKKβ, and AMPK (Appendix Fig. S8C), confirming the essential role of CTRP9 in initiating the AdipoR1–Ca2+–CaMKKβ signaling cascade in response to bacterial challenge.