nucleolin
/ˌnjuːklɪˈəʊlɪn/ /njuːˈklɪəlɪn/Biochemistry
noun
Specifically. A protein found abundantly in the nucleoli of cells, associated with the transcription of ribosomal RNA and the assembly of ribosomes.
Origin
Early 20th century (in an earlier sense). From nucleolus + -in.