M15344 2008 (Acute b-cell leukemia [mh] AND (pre [ti] OR precursor [ti]) AND leukemia, pre-b-cell [mh] AND+MEDLINE+[sb]) OR (Acute b-cell leukemia [mh] AND (pre [ti] OR precursor [ti]) AND leukemia, pre-b-cell [mh] AND+jsubsetom) M15360 2008 embryo [majr:noexp] NOT (invertebrates [mh] OR vertebrates [mh]) NOT jsubsetom AND+MEDLINE+[sb]