BEST1 and neoplasm: Besides playing an important role in the chemotaxis of tumor‐infiltrated monocytes, VEGF‐A stimulates autophosphorylation and downstream signal transduction of VEGFR‐1 and VEGFR‐2 in monocytes.[26, 43, 44] Once VEGFR is activated, MAPK pathway is activated to regulate BEST1 gene expression, as well as IP3 induction to facilitate endoplasmic reticulum calcium store release.