SPARCL1 and malignant tumor of parathyroid gland: In the parathyroid, we observe high expression levels of Sparcl1 (Fig. 1g), a gene frequently downregulated in epithelial cancers, including parathyroid cancer, leading to increased proliferation and cell cycle progression42; therefore, our results indicate this gene could be performing an anti-growth or anti-proliferative function during early parathyroid development.