CA4 and lung cancer: Cytotoxicity of the series of cis-restricted triazole analogues of CA-4 was investigated as described in the Materials and Methods section by growth inhibition assays, using two types of tumor cells, namely, the human colon cancer cell line HT-29 and human lung cancer cell line A-549, as well as one normal cell line, the human embryonic kidney cell line HEK-293 [29], as a way to estimate the selectivity of the compounds for tumor cells.