ST7L (suppression of tumorigenicity 7 like) is a tumor suppressor gene located on chromosome 1 that functions as a negative regulator of cell growth. The gene encodes a 575-amino acid protein containing leucine zipper domains and tyrosine phosphorylation sites, showing 72.1% amino acid identity with its paralog ST7 1. ST7L undergoes alternative splicing to produce multiple isoforms and is clustered with WNT2B in a tail-to-tail arrangement, suggesting evolutionary duplication from an ancestral ST7-WNT2 gene cluster 1. The protein acts as a tumor suppressor by modulating the Wnt/β-catenin signaling pathway. ST7L suppresses β-catenin/TCF-4 transcriptional activity, thereby inhibiting cell proliferation and invasion 2. In cancer contexts, ST7L expression is frequently downregulated through microRNA-mediated mechanisms, including targeting by miR-24 in glioma 2, miR-23a in ovarian cancer 3, and miR-378 in cervical cancer 4. Loss of ST7L function contributes to malignant transformation by activating oncogenic pathways including NF-κB and WNT/MAPK signaling 3. The gene's location in chromosome 1, a region frequently altered in various cancers including breast, lung, and gastrointestinal tumors, supports its role as a tumor suppressor 1.