CD8A and cancer: found that cytotoxic CD8+ T cells (CTLs) maintained CD103 expression by self-secreting TGFβ1 in an activated form, which improved cellular TCR sensitivity as well as cell migration, contributing to the rapid recognition of autologous tumor cell surface antigens and toxic efficacy of CD103+ tumor-specific CTLs in killing tumor cells; however, this population was more susceptible to apoptosis during prolonged exposure to the cancer microenvironment (i.e., the proportion of CD103+ tumor-specific CTLs decreased as the tumor grew).