Yin X, et al. - Studying a total of 118 gastric gastrointestinal stromal tumors (GISTs) patients, researchers investigated the expression of CD55 in gastric GISTs and determined how it is correlated with clinicopathologic characteristics and prognosis. Using immunohistochemistry, they identified 44 (37.3%) as positive for CD55 expression. Findings revealed a close association of positive CD55 expression in gastric GISTs with tumor size (13.52±7.35 vs 5.07±1.90 cm, respectively), Ki 67 labeling index, mitotic counts, NIH risk classification, PLR, and metastasis at initial diagnosis. Cox multivariate survival analysis showed that mitotic counts, Ki 67 labeling index, and CD55 expression were independent predictors of PFS for gastric GISTs. As per Cox multivariate survival analysis, the independent predictive value of mitotic counts, Ki 67 labeling index, and CD55 expression for PFS for gastric GISTs was suggested. These findings suggest the potential value of CD55 as a prognostic marker in gastric GISTs patients.