HLA-C and neoplasm: Although staining with peptide–MHC tetramers provides a direct estimate for the number of TAA-specific T cells present in vivo, and intensity of tetramer staining has been employed as a parameter for isolation of high-RE, tumor-lytic T cells [27], staining intensity does not correlate well with RE or tumor-lytic potential [28,29], and cannot be considered a reliable indicator for the functional status of TAA-specific T cells.