Abstract Background Cerebellar granule cell precursors are specifically generated within the hindbrain segment. rhombomere 1. which is bounded rostrally by the midbrain/hindbrain isthmus and caudally by the boundary of the Hoxa2 expression domain. While graded signals from the isthmus have a demonstrable patterning role within this region. https://thebrickes.shop/product-category/trim-kit/