CD38 and neoplasm: Fluorescence intensities of DiR‐labelled EVs and CD38‐EVs (n = 3 per group), as well as PKH‐26‐labelled EVs and CD38‐EVs (n = 3 per group), were measured at various times using the FMP in vivo imaging system and ex vivo tumour tissue observation, comparing the tumour‐targeting efficiency of CD38‐EVsMNs with CD38‐EVsi.v.