DICER1 and DICER1-related tumor predisposition: In addition, co-occurring DICER1 mutations have been similarly identified in TC patients not related to DICER1 syndrome (28, 51–53) and also in COSMIC patients (Figure 3C) where RNase IIIb domain mutations (at codons E1705 and D1709) co-occur with a second nonsense/frameshift_nonsense mutation.