4CQH:
reference: An improved monomeric infrared fluorescent protein for neuronal and tumour brain imaging., Yu D, Gustafson WC, Han C, Lafaye C, Noirclerc-Savoye M, Ge WP, Thayer DA, Huang H, Kornberg TB, Royant A, Jan LY, Jan YN, Weiss WA, Shu X, Nat Commun. 2014 May 15;5:3626. doi: 10.1038/ncomms4626. PMID: 24832154

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