PTGFRN and cancer: Since PTGFRN is expressed in certain cancers with no expression in normal tissues, these results indicate that PTGFRN could be a valuable new ADC target as PTGFRN negative cells showed no response to the 8C7‐ADC, while tumours that express low level of PTGFRN, such as the MSTO‐211H tumours, still demonstrated a statistically significant response to the 8C7‐ADC.