As a negative regulator of T cells, the immune checkpoint molecule B7H4 induces epithelial-mesenchymal transition in ICCA, thereby facilitating tumor cell invasion and metastasis through the activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. The gene discussed is VTCN1; the disease is infantile convulsions and choreoathetosis.