CD8A and infection: To investigate the potential interplay between circulating memory and Trm CD8+ T cells in anti-tumour immunity we first infected mice with rVACV-OVA by different routes and measured circulating and resident memory at 30 d.p.i. Frequencies of endogenous OVA-specific circulating memory T cells were similar regardless the infection route (Fig. 1a and Supplementary Fig. 1a).