Fusion rates and predicted neoantigen load varied significantly between CDK12
biallelic LOF tumors across cancer types, highlighting the value of biomarkers with a
quantitative, phenotypic and/or immunogenic readout.
• Co-occurrence of dMMR/MSI-High with CDK12 biallelic LOF correlated with a lower
fusion rate and recurrent CDK12 frameshift mutations at poly-nucleotide tracts,
suggesting CDK12 mutations are a secondary effect in these tumors.
• We propose that fusion rates are linked to CDK12 alterations and may serve as useful
biomarker to enhance our ability to identify responders of ICI therapy.