NME1 and breast carcinoma: There is evidence to support an intracellular role for NM23/NDPK in tumour metastasis (Hamby et al, 2000; Roymans et al, 2002), and high tissue levels of NDPK-A protein have been found in patients with breast carcinoma (Heimann et al, 1998; Sauer et al, 1998).