As a reference, the SK-RC-52 renal cell carcinoma model, which constitutively overexpresses CAIX due to the VHL mutation, had a much higher CAIX positive fraction of 0.59 ± 0.15 (compared to SCCNij153 p = 0.03) (Fig. 4). Here, CA9 is linked to hereditary clear cell renal cell carcinoma.