Radioresistance is a frustrating obstacle for patients with colorectal cancers 
(CRCs) undergoing radiotherapy. There is an urgent need to find an effective 
agent to increase the sensitivity of CRCs to radiation. Honokiol, an active 
compound purified from Magnolia, was found to radiosensitize colorectal cancer 
cells both in vitro and in vivo. However, the mechanisms control important 
signaling that enhances radiosensitivity is currently unknown. In this study, we 
have reviewed important signaling pathways that are closely related to 
radiosensitization, such as cell cycle arrest, tumor angiogenesis, JAK/STAT3 
signaling pathway and Mismatch repair. Studies show that honokiol can interfere 
with these pathways at different levels. With overall analysis, it may bring 
light on finding the possible mechanism by which honokiol acts as a 
radiosensitizing agent for CRCs.