CD8A and neoplasm: Whereas in most studies β-catenin hyperactivity has been found as a primary, innate resistance mechanism, it was recently described in a patient in which the only non-regressing metastasis displayed an enhanced β-catenin signaling and was consequently not infiltrated by antigen-specific CD8+ T cells that were still present in the patients ́ circulation and that were able to recognize in vitro tumor cells derived from that metastasis [27].