This review provides a comprehensive overview of the recent advancements in research on ATF4 (Activating Transcription Factor 4) within the field of oncology. As a crucial transcription factor, ATF4 has garnered increasing attention for its role in cancer research. The review begins with an exploration of the regulatory mechanisms of ATF4, including its transcriptional control, post-translational modifications, and interactions with other transcription factors. It then highlights key research findings on ATF4's involvement in various aspects of tumor biology, such as cell proliferation, differentiation, apoptosis and survival, invasion and metastasis, and the tumor microenvironment. Furthermore, the review discusses the potential of targeting ATF4 as a novel therapeutic strategy for cancer treatment. It also explores how ATF4's interactions with existing anticancer drugs could inform the development of more effective therapeutic agents. By elucidating the role of ATF4 in tumor biology and its potential clinical applications, this review aims to provide new insights and strategies for cancer treatment.