To establish whether the PIK3CA public NeoAg is spontaneously immunogenic, we collected PBMC samples from n = 14 HLA-A*03:01+ patients with a history of a Mut PIK3CA cancer identified using MSK-Integrated Mutation Profiling of Actionable Cancer Targets (IMPACT) (Extended Data Fig. 8 and Supplementary Fig. 12)43–45. This evidence concerns the gene HLA-A and cancer.