ANPEP and cancer: This observation is consistent to our recent report which demonstrated the existence cancer‐specific CD13 glycoforms in human breast CDX.[56] Interestingly, treatment of spheroids with ICT10336 for 4 days (at non‐toxic concentrations to normal cells, Table S1, Supporting Information) significantly diminished the fluorogenic response of the hypoxia probe compared to DMSO control and AZD6738‐treated spheroids (Figure 10C,D).