ST7 (suppression of tumorigenicity 7) is a putative tumor suppressor gene located on chromosome 7. The gene encodes a protein that may act as a tumor suppressor, as demonstrated by functional studies showing that ST7 cDNA introduction into prostate cancer cells (PC3) abrogated their in vivo tumorigenicity without affecting in vitro proliferation 1. ST7 is ubiquitously expressed in human tissues and contains conserved domains (S7H1, S7H2, S7H3) shared with homologous genes across species 12. The gene is clustered with WNT2 on chromosome 7 and has a homologous counterpart ST7R on chromosome 7 2. Loss of heterozygosity (LOH) at the 7q31 region containing ST7 is frequently observed in various malignancies including esophageal carcinomas (28% of cases) and breast tumors 31. However, the tumor suppressor role remains controversial, as multiple studies have failed to identify somatic mutations in the ST7 coding sequence in colorectal cancers, myeloid tumors, and esophageal carcinomas despite LOH at this locus 453. Additionally, ST7 has been implicated in neurogenetic disorders through whole-exome sequencing studies 6.