SOCS3 and neoplasm: To determine if the recognized epitopes were endogenously processed and presented by tumor cells, we re-stimulated individual peptide-expanded TILs with matched epithelial cell lines grown from the same patient tumor ascites samples and observed stimulation of TILs specific for both MOB1A epitopes and the SOCS3 epitope by 2 patient-derived tumors (OV355 and OV486, Fig. 3b).