Figure 1.

HER3 expression in cancer, and HER3 peptide screening of ECD and ICD class II peptide libraries. A, Expression of HER3 mRNA in normal (N) and tumor (T) tissues obtained from RNA-seq data from the GDC across cancer types (see Materials and Methods). B, Correlation between percentage of HER3 expression and overall patient survival (in months) in breast cancer. Samples were sorted in the descending order of HER3 expression and put into two groups: high HER3 (red) and low HER3 (blue). C, Correlation of overall patient survival with high HER3 (red) versus low HER3 (blue) expression in melanoma. P value indicated in individual graphs. D and E, IFN-γ production at each screening step for sample 1 [normal donor (ND) 8; D] and sample 2 (ND 9; E) when stimulated with ECD peptides. F and G, IFN-γ production at each screening step for sample 3 (ND 3; F) and sample 4 (ND 5; G) upon stimulation with ICD peptides. D–G, IFN-γ response to negative peptide control (black) compared with HER3 peptides (red) with an immunogenic response threshold of ≥1.5-fold increase. Data represented as mean ± SEM with statistical significance determined using a multiple t test without correction for multiple comparisons. Each row was analyzed individually, without assuming consistent SD. *, P < 0.05; **, P < 0.01; ***, P < 0.001.