TABLE 2.

Molecular alterations in thymic epithelial tumor (TET).

WHO classification	Structural variation	Gene mutation
Type A	Chromosome deletion: 6q25.2–25.3, 2, 4, 6q, 13, 6p21 Chromosome translocation: t (15;22) (p11; q11)	GTF2I, TP53, HRAS, EGFR, STK11, SMARCB1, TET2, PDGHRA, RUNX1, etc.
Type AB	Chromosome deletion: 2.4, 5q21‐22, 6p21, 6q25.2–25.3, 7p15.3, 8p, 13q14.3, 16q, 18
Type B1	Chromosome deletion: 1p, 1q, 3q, 4, 5, 6q, 8, 13, 18 Chromosome duplication: 9q
Type B2	Chromosome deletion: 6q25.2–25.3和3p Chromosome duplication: 1q
Type B3	Chromosome deletion: 3p, 6, 6q25.2–25.3, 9p, 11q42.qter, 13q, 16q, 17p, 9q21.3 (CDKN2A/CDKN2B) Chromosome duplication: 1q, 4, 5, 7, 8, 9q, 17q, X, 18q21.33 (BCL2)
TC (type C)	Chromosome deletion: 3p, 6, 6q25.2–25.3, 9p, 13q, 14, 16q, 17p, 9q21.3 (CDKN2A/ CDKN2B) Chromosome duplication: 1q, 4, 5, 7, 8, 9q, 12, 15, 17q, 18, 20, 18q21.33 (BCL2)	GTF2I, TP53, KIT, KRAS, NRAS, ROS1, DDR2, PDGFRA, IGF1R, ERBB2, ROS1, ALK, ATM, CDKN2A, FGFR3, HRAS, PTEN, etc.

Abbreviations: TC, thymic carcinoma.