VEGFA and nephrolithiasis: Here, leveraging a Drosophila gut tumor model, we demonstrate that tumor-secreted PDGF- and VEGF-related factor 1 (Pvf1) stimulates PDGF/VEGF signaling in the fly malpighian tubules (MTs), a renal system functionally equivalent to the vertebrate kidney17,18, leading to formation of kidney stones, ascites/bloating, and uric acid accumulation.