CD44 and neoplasm: Positive expressions of CD44 did not predict neoplasm metastasis (RR = 1.36, 95% CI: 1.00–1.84, P = 0.50), and the results indicated that higher expression of CD44 could not predict poorer survival in osteosarcoma with the pooled HR of 0.55 (95% CI: 0.27–1.13, P = 0.47).