Double immunofluorescence of three human ACP samples revealed a variable degree of co-localisation between Ki67 and pERK1/2 expression (Fig. 4d) (tumour 1: 80%, 45 co-expressing cells out of 56 Ki67+ve cells; tumour 2: 44%, 26 co-expressing/59 Ki67+ve cells; tumour 3: 15%, 5 co-expressing/33 Ki67+ve cells). Here, MKI67 is linked to neoplasm.