Focus issue: fine-tuning Hedgehog signaling in development and disease

Hedgehog (Hh) signaling plays varied and critical roles in animal development, homeostasis, and disease. The core components of the canonical pathway and many key modulators of signaling have been identified, as have mechanisms by which the quantity and quality of signaling through the pathway are modulated. New research reveals details about generation and interpretation of Hh gradients, noncanonical Hh signaling, and fine-tuning the biological response to Hh signaling, particularly in the context of human diseases such as cancer.