Similarly, in a second tumor model, only T cells transduced with the PIK3CAE545K-specific TCR, suppressed (p = 0.004) the growth of the cell line CCL-225, which also naturally expressed the E545K mutant protein, following transduction with HLA-DRB1*04:01 (Fig. 3I). Here, HLA-DRB1 is linked to neoplasm.