DICER1 Sequence Analysis in FFPE Tumor Tissue

After careful manual microdissection, DNA was analyzed from FFPE tumor tissue using the Maxwell© 16 system (Promega, Madison, WI, USA) according to manufacturer’s instructions. DICER1 sequence analysis was performed using the QIAseq Targeted Human Comprehensive Cancer Panel according to manufacturer’s instructions (the list of the 160 genes is shown in the supplementary file). Bioinformatic evaluation of the sequencing data, including variant calling and annotation, was done with the CLC Genomics Workbench (QIAGEN, Redwood City, CA, USA). Low-quality variants with a score under 200 were filtered out, as well as variants in non-protein-coding regions, synonymous variants, and those present in GnomAD with an allele frequency of over 1%. The remaining variants were assessed for pathogenicity according to ACMG/AMP criteria. The DICER1 variants were classified as described previously [6 (link)].