Comparison of TIL repertoires with the corresponding sentinel LN repertoires. (A) Number of TCRs out of the total TIL repertoire that were also present in the tumor-infiltrated (LN+, n = 5) or non–tumor-infiltrated (LN−, n = 5) sentinel LN repertoires is shown as a percentage (*P = 0.01). Patient 20 presented with tumors in each breast. The tumors were resected, along with the sentinel LN from each axilla. (B) Repertoires of the TILs and LNs [either left (L) or right (R)] were compared with each other and percentage of overlap was determined as in A. (C) Twenty-nine TCRs shared between the tumor repertoires of patient 20 are shown, with TCRs found in all five (blue), four (red), three (green), or TIL-only (dark gray) repertoire. TCRs not found in a specific repertoire are represented in light gray. n, total number of unique TCR sequences in the TIL.