To determine whether the reported reciprocal effect of PDEF on LASP-1 in non-invasive and invasive breast cancer cell lines (Turner et al, 2008) is transferable to breast tumour patient samples, we evaluated 35 primary breast cancer tissues for PDEF expression; 17 with known high (⩾8) LASP-1 IRS and 18 specimens with low (⩽3) LASP-1-IRS. This evidence concerns the gene IARS1 and breast carcinoma.