Additional co-occurring alterations included ARID1A, ATM, CDKN2A, EPHA3, MYC, NFE, PTEN, RB1, SLIT2, and SPTA1. Two cases had an alteration involving the MAPK pathway (KRAS G12D and KRAS Q61R); there were no other alterations involving RAF, MEK, or ERK. The mean tumor mutational burden (TMB) was 3.81 mutations per DNA megabase (range 0.87-7.2 mut/Mb). The gene discussed is ARID1A; the disease is neoplasm.