CD274 and neoplasm: Considering that CODEC WGS showed 290-fold lower residual indel frequencies than standard WGS (Extended Data Fig. 9) and that Illumina NGS is known to have an especially high indel error rate at DNA homopolymers, we explored if CODEC might improve MSI detection, which is an FDA-approved indication for immunotherapy (anti-PD1/PDL1) but challenging to detect at low tumor fraction such as from liquid biopsies40.