However, although neurotrophins are conceptually linked to IESS pathogenesis, the supplied literature does not include primary mechanistic studies detailing canonical receptor–signaling cascades (e.g., BDNF/TrkB, NGF/TrkA, GDNF/GFRα-RET), regional developmental expression, or pathway-specific contributions to spasms. This evidence concerns the gene BDNF and infantile spasms.