Simetryn is a triazine herbicide that exerts teratogenicity. Simetryn inhibits photosynthesis by blocking electron transfer in the chloroplast photosystem II and activates the MEK/Erk signaling pathway. Simetryn triggers vascular and developmental abnormalities in zebrafish and tadpoles, suppresses proliferation, enhances apoptosis, and induces malformations. Simetryn serves as a tool to establish a zebrafish model for studying arteriovenous malformations and related pathogenesis. Simetryn controls paddy weeds and can be used for research on developmental and vascular disorders[1][2].