Compounds 1–36 were also tested in doxorubicin-resistant human adenocarcinoma colon cells (HT29/DOX) and in doxorubicin-resistant non-small cell lung cancer cells (A549/DOX), that overexpress both P-gp and hCA XII [19], to study the effect of these dual P-gp/hCA XII inhibitors in a specific environment where the two target proteins coexist. Here, PGP is linked to adenocarcinoma.