SFRP4 and neoplasm: In addition, there were pathways such as the Wnt signaling pathway (frizzled class receptor 6 (FZD6), peroxisome proliferator-activated receptor delta (PPARD), and secreted frizzled-related protein 4 (SFRP4)), gap junction (adenylate cyclase 8 (ADCY8) and neural tissue-specific F-actin-binding protein I (Neurabin-1, PPP1R9A)), and cell adhesion molecules (v-set immunoregulatory receptor (VSIR) and leukocyte antigen c (HLA-C)) associated with tumor metastasis.