All the various logic gates have been observed in (DNA) gene expression studies - both naturally occurring and bioengineered tools. In particular there are tons

All the various logic gates have been observed in (DNA) gene expression studies - both naturally occurring and bioengineered tools. In particular there are tons of bioengineered tools for inducible gene expression that have all manner of gating mechanisms for precise temporal control of expression (triggered by behavior, environment, drug, elapsed time, etc.). Reading... https://en.wikipedia.org/wiki/Cre-Lox_recombination?wprov=sfti1 https://en.wikipedia.org/wiki/Cre-Lox_recombination?wprov=sf... https://en.wikipedia.org/wiki/Receptor_activated_solely_by_a_synthetic_ligand?wprov=sfti1 https://en.wikipedia.org/wiki/Receptor_activated_solely_by_a... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802553/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802553/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4772104/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4772104/