To assess the association between ARID1A intrinsic mutations and worse outcome in anti-EGFR vs. bevacizumab-treated patients in an independent “real-world” dataset, we investigated the relationship between ARID1A mutational status and outcome in anti-EGFR (cetuximab or panitumumab)- vs. bevacizumab-treated patients from the nationwide (US-based) de-identified Flatiron Health-Foundation Medicine CRC clinico-genomic database (FH-FMI CGDB)27–29. Here, EGFR is linked to colorectal carcinoma.