RAB9BP1 and neoplasm: The CNVs in MTCS1 were mainly associated with tumor cell proliferation, such as the amplification of 5q35.1 (STC2), 5q15 (EII2), and 5q21.3(RAB9BP1) and the deletion of 3p25.3 (VGLL4 and ATG7), 2q35 (MREG), and 2q37.1 (AGXT, ALPI, and ALPP) (Supporting Information: Figure S5B‐D).