In patients with breast cancer, TILs have been shown to be associated with anti-oestrogen therapy resistance; in a neoadjuvant setting of ER+ postmenopausal women with early-stage ER+ breast cancer (I–IIIB), a poor aromatase inhibitor response was strongly associated with the expression of inflammatory response-related pathways and lymphocytic infiltration (Miller et al. 2009, Dunbier et al. 2013). The gene discussed is CYP19A1; the disease is breast cancer.