x expressed in y if and only if there is a gene expression process (GO:0010467) that occurs in y, and one of the following holds: (i) x is a gene, and x is transcribed into a transcript as part of the gene expression process (ii) x is a transcript, and the transcription of x is part of the gene expression process (iii) x is a mature gene product such as a protein, and x was translated or otherwise processes from a transcript that was transcribed as part of this gene expression process

'neural crest cell' SubClassOf expresses some 'Wnt1 gene'

http://purl.obolibrary.org/obo/IAO_0000125

http://purl.obolibrary.org/obo/cl.owl

Chris Mungall