In hepatocellular carcinoma, Yuan et al. observed that high PAP expression was associated with low-grade tumors and favorable prognosis, whereas Reg/PSP overexpression—often accompanied by p53 mutations—was linked to high-grade tumors and worse outcomes [79] In contrast, in gallbladder carcinoma, Tamura et al. found that high PSP levels were associated with malignant transformation via intestinal metaplasia but paradoxically correlated with better survival after surgery, suggesting context-dependent prognostic value [80]. This evidence concerns the gene REG1A and gallbladder carcinoma.