Treatment with SEL-based regimens induced the expression of T-cell activation markers in responding compared with relapsed samples. (A) Volcano plot shows the differential expression of all assessed proteins in CD3⁺ T cells comparing post-SEL treatment samples taken at the time of PD vs a period of clinical response. Normalized expression levels of pAKT1 (B), CD127 (C), granzyme B (D), CD44 (E), EGFR (F), and STING (G) showed significant upregulation in samples from patients responding while on treatment compared with those at time of relapse (PD). GZMB, granzyme B.