Patched 2 receptor gene (PTCH2), a tumor suppressor in the Sonic Hedgehog (SHH) signaling pathway, appeared to be the most significantly upregulated gene in this group, implying that decreased expression of PTCH2 due to chr1p loss may result in increased aggressiveness of NF2-2 meningiomas. The gene discussed is SHH; the disease is meningioma.