PLAC1 and neoplasm: As for lymph node metastasis and tumor relapse, we found that compared to primary lesions, epithelial cells in metastatic lesions exhibited higher Plac1 expression level (p < 0.0001 both in GSE182227[21] and GSE188737[20]) (Figure S1G, Supporting Information) and compared to primary tumors, recurrent tumors showed higher Plac1 expression level (p = 0.038 in GSE173855[22]) (Figure S1H, Supporting Information).