This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetic Basics Of Carcinogenesis, Subject name: Pathology
Which of the following tumor suppressor genes act by inhibition of Hedgehog signaling pathway? 
Select and explain. 
A. PTCH, B. SDHB, C. BRCA1, D. CDKN2A
A: PTCH
Answer: A: PTCH 
Explanation: Tumor suppressor genes and associated Familial Syndromes and Cancers -PTCH:-Gene acts by inhibiting Hedgehog signaling pathway Patched protein Causes:- Gorlin syndrome (BCC, Medulloblastoma,severe benign tumor) -SDHB:-Inhibitors of "Pro-growth" programs of Metabolism and Angiogenesis Succinate dehydrogenase complex subunits B and D Causes:-Familial paraganglioma, familial pheochromocytoma -CDKN2A:-Inhibitors of cell cycle progression, causes Familial melanoma -BRCA1:-DNA Repair factors, causes Familial breast and ovarian carcinoma; carcinomas of male breast