SREBF1 and osteosarcoma: ROCK1, which is a key kinase governing cytoskeletal dynamics, cell motility, and tumor microenvironment remodeling,[26] has been implicated in COPII vesicle biogenesis through macrolevel regulation of SEC23A (SEC23 Homolog A, COPII Coat Complex Component) expression.[42] Accumulating evidence implicates ROCK1 in diverse malignancies—including ESCC, prostate and gastric cancers, and osteosarcoma.[43, 44, 45] Here, we show that ROCK1 engages a COPII‐dependent trafficking route to activate SREBP1, thereby rewiring lipogenic programmes and promoting ESCC progression.