CD4 and neoplasm: Our LSM-SIM imaging achieved a spatial resolution of approximately 1.7 ± 0.2 μm × 1.1 ± 0.2 μm × 1.6 ± 0.1 μm, making it suitable for resolving single cells in vivo as shown for CD4+ and OX40+ cells in the tumour microenvironment by intratumourally injected CpG (refs. 18,27).