CAPN1 and ovarian cancer: Fenouille and colleagues observed different calpain expression levels between the chemo-resistant cells and their parental counterparts (Fenouille et al. 2012); however, in the current in vitro study, chemo-sensitive ovarian cancer cells (i.e. A2780 and PEO1 cells) and their resistant counterparts (i.e. A2780-cis and PEO4 cells, respectively) expressed similar levels of calpain-1, -2, and -4, and calpastatin.