TGF-beta1 can induce its own expression by an autoregulatory mechanism. In this issue of Molecular Cell, Ventura et al. (2004) show, using JNK-deficient fibroblasts, that JNK negatively regulates TGF-beta1 gene expression and, consequently, autocrine TGF-beta signaling. The results highlight the contributions of JNK signaling in the control of TGF-beta expression and signaling, and of autocrine TGF-beta signaling in the JNK-regulated changes in cell behavior.