(1) In the digestive system tumor subgroup (HR = 1.55, 95% CI: 1.22–1.88, p < 0.001) and the non-digestive system tumor subgroup (HR = 1.46, 95% CI: 1.26–1.65, p < 0.001), high ST8SIA6-AS1 expression was significantly correlated with worse OS (Figure 3A). Here, ST8SIA6 is linked to digestive system neoplasm.