CD4 and neoplasm: Intravital two-photon microscopy demonstrated that eGFP+ TRP-1 CD4+ T cells preferentially arrested and engaged in long-lasting close interactions with CD11c-Venus+ immune cells only in HCmel12 CRISPR-ctrl tumours, but not in HCmel12 Trp1-KO tumours (Fig. 2h,i, Extended Data Fig. 5g,h and Supplementary Video 5).