Between November 2010 and May 2014, 20 cases—17 thymomas and 3 thymic carcinomas (including 2 squamous and 1 neuroendocrine carcinoma)—were newly sequenced from surgically removed TETs at Seoul National University Hospital, with written informed consent. Tumors and normal tissues were carefully separated and immediately preserved in liquid nitrogen after resection. DNA and RNA were extracted from the tumors, adjacent normal tissues, and/or blood samples. Libraries for WES were prepared using the SureSelect XT (Human All Exon + UTR v5) Library Prep Kit following standard Illumina protocols.
