Chloride Intracellular Channels (CLICs) are a family of 6 proteins that have in common a C-terminal CLIC module and chloride-selective ion channel activity. CLIC1 is a 241 amino-acid protein involved in the regulation of the cell cycle, in particular it is overexpressed in a number of cancer cells. However, to date little information exists as to its structure and the factors that influence its insertion into membranes. Here we propose to study non-oxidised CLIC1 at pH 5.5 and 7.4 against two membrane compositions (i) PC:PE:Chol and (ii) PC:Chol. This will be used in combination with a broad range of ongoing biophysical characterisation to establish the mechanism of CLIC1 chloride channel formation, as well as the factors influencing it. This will be an initial step to understand how CLIC1 functions in tumour cells and will allow specific treatments to be designed to interrupt it.