We thank the Surgery Branch TIL Laboratory and clinical team for generating TIL, and patients enrolled in our clinical protocols. Support from CCR Single Cell Analysis Facility was funded by FNLCR Contract HHSN261200800001E. This work utilized the computational resources of the NIH HPC Biowulf cluster (http://hpc.nih.gov). We also thank NIDAP for providing additional computational support and the CCR Genomics Core for next-generation sequencing support. Funding: This research was supported by the Center for Cancer Research intramural research program of the National Cancer Institute. This project has been funded in part with federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. 75N91019D00024. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. Author contributions: F.J.L., S.K., P.F.R., and S.A.R. conceived the study and designed experiments; F.J.L., S.K., N.B.P., and S.L.G. curated patient samples for inclusion; F.J.L., S.K., R.Y., N.B.P., P.D.C., N.Z., N.L., M.R.P., Z.Y., N.R.V., K.J.H, Y.C.L., Z.Z., L.J., J.J.G., S.S., V.K.H., A.R.C., A.S., R.V.M., B.G., S.Kivitz., S.K.N., B.C.P., Y.F.L., M.F., L.T.N., S.R., M.L.S., S.T.L, R.S., C.T., A.P., T.D.P., R.B., and M.C.K. performed experiments; F.J.L., S.K., R.Y., S.S., N.B.P., K.H., J.C.Y. and P.D.C. performed data analysis; and F.J.L., S.K., and S.A.R. wrote the manuscript with input from all authors. Competing interests: Authors declare no competing interests. F.J.L., S.K., R.Y., K.H., J.C.Y., P.F.R., and S.A.R. are listed as inventors on a patent application (US Provisional Patent Application No. 62/992,701, PCT Patent Application No. PCT/US2021/023240) submitted by NCI that covers the use of NeoTCR signatures to identify antitumor TCRs. Data and materials availability: All data are available in the main text or the supplementary materials. Sequencing data generated as part of this study are available on dbGaP under accession number phs002748.v1.p1. Previously published tumor exome and RNA sequencing data can be found on dbGaP, accession numbers phs002735.v1.p1 and phs001003.v2.p1.