CA9 and pancreatic ductal adenocarcinoma: Among the several chemotypes studied for selective inhibition of tumour-associated CAs, the licenced SLC-0111 (Figure 1), a ureido-bearing p-benzenesulfonamide CA IX inhibitor, is in Phase Ib/II clinical trial in combination with gemcitabine in pancreatic ductal adenocarcinoma patients with expression of CA IX (for both dose escalation and dose expansion) (https://clinicaltrials.gov/show/NCT03450018).24