O Gnat

https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:49668
http://www.hmdb.ca/metabolites/HMDB0014462
http://www.genome.jp/dbget-bin/www_bget?drug:D01977
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=123631
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46508649
https://www.chemspider.com/Chemical-Structure.110217.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=5447
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=328134
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=49668
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL939
https://zinc.docking.org/substances/ZINC000019632614
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DAP000657
http://www.pharmgkb.org/drug/PA131301952
https://www.ebi.ac.uk/pdbe-srv/pdbechem/chemicalCompound/show/IRE
http://www.rxlist.com/cgi/generic3/iressa.htm
https://www.drugs.com/cdi/gefitinib.html
https://en.wikipedia.org/wiki/Gefitinib