EIF1AX and thyroid gland undifferentiated (anaplastic) carcinoma: These include DAXX, NF1, ARHGAP35, MADCAM1, ATXN1, UBXN11, TSC1/2, and CDKN1A mutations, mutations characteristic of FTC including RAS, PIK3CA, and PTEN mutations, and those that are characteristic of poorly differentiated and anaplastic thyroid carcinoma including TERT promoter, PIK3CA, PTEN, EIF1AX, ATM, and TP53 (Ganly et al. 2013, 2018, Corver et al. 2018, Jalaly & Baloch 2020, Kumari et al. 2020, Santana et al. 2020, Doerfler et al. 2021).