It was established that: (a) AML blasts without maturation (MO type) and monoblasts did not synthesize NCA; (b) individual blasts of AML with features of maturation (M1, M2 types) and some myeloblasts of CGL-BC exhibited a limited ability to express cytoplasmic NCA; (c) the number of NCA-containing cells increased in the more mature granulocyte fractions isolated on Ficoll-Hypaque density-gradients; (d) myelocytic NCA is immunologically related to NCA isolated from lung tissue and (e) CEA is undetectable in the myelocytic cell series. Here, CEACAM5 is linked to acute myeloid leukemia.