Organ size control is the biological mechanisms that determine, limit, and restore the characteristic mass and dimensions of an organ. It is governed by the precise coordination of cell proliferation, death, and differentiation. It represents a fundamental problem in developmental biology, tissue homeostasis and regeneration: how does an organism "know" when an organ is the right size, and how does it halt growth once that size is reached? These decisions emerge from the dynamic interplay of molecular signaling networks, including the Hippo pathway, nutrient-sensing checkpoints, integrated with mechanical cues from the tissue microenvironment. Tumorigenesis, in essence, represents a catastrophic failure of these size-control checkpoints. 

Guo laboratory investigates the molecular mechanisms of organ size control and its corruption in cancer. Guo laboratory employs an integrated platform of mouse genetic models, cell culture systems, and Drosophila developmental genetics. By combining CRISPR-based functional genomics, advanced cell biology, bioinformatics, and multi-omics profiling, Guo laboratory aims to decode the regulatory networks that set organ-size setpoints and to identify how their dysregulation drives tumorigenesis. Guo laboratory's research program focuses on three interconnected directions: (1) elucidating the role of the Hippo signaling pathway in development, homeostasis, and tumorigenesis; (2) investigating how mechanical forces and tissue architecture modulate Hippo pathway activity to govern tissue growth and tumor initiation; (3) conducting in vivo CRISPR screens to discover novel size-control genes and therapeutic targets.