Furthermore, the perichondral spindle cells and marrow osteoblasts/fibroblasts of BPOP showed stronger immunoreaction of PCNA, p53, β-catenin, BCL2, pAKT, survivin, CEA, EMA, pan-K, and S-100 than the tumor cells of osteochondroma. The gene discussed is ADA2; the disease is Osteochondroma.