Modifiers matching ligand:

• bound,
• inorganic,
• important,
• hydrophobic,
• natural,
• exogenous,
• biological,
• endogenous,
• weak,
• psychoactive,
• simple,
• physiologic,
• axial,
• lipophilic,
• acidic,
• charged,
• nonsteroidal,
• organic,
• synthetic,
• cationic,
• psychedelic,
• atomic,
• hydrophilic,
• metal,
• soft,
• additional,
• uncharged,
• small,
• active,
• relevant,
• common,
• anionic,
• binding,
• ancillary,
• potent,
• environmental,
• extracellular,
• strong,
• complex,
• polar,
• neutral,
• hard,
• nonmetal,
• functional,
• complementary,
• cellular,
• ionic,
• physiological,
• base,
• external,

Simple categories matching exogenous:

• base,
• substance,
• input,
• agent,
• inhibitor,
• source,
• stimulus,
• solute,
• compound,
• substrate,
• authority,
• event,
• pathogen,
• particle,
• antioxidant,
• molecule,
• proteinase,
• phosphoprotein,
• retrovirus,
• buffer,
• condition,
• protease,
• activator,
• system,
• glucocorticoid,
• cause,
• antigen,
• variable,
• amphetamine,
• process,
• estrogen,
• acid,
• material,
• signal,
• factor,
• protein,
• corticosteroid,
• hexose,
• steroid,
• occurrence,
• cofactor,
• toxin,
• change,
• demand,
• shock,
• poison,
• enzyme,
• amine,
• chemical,
• catecholamine,
• carbohydrate,
• macromolecule,
• toxicant,
• food,
• asthma,
• carcinogen,
• development,
• cytokine,
• disturbance,
• polysaccharide,
• intoxicant,
• acceptor,
• sugar,
• inducer,
• hormone,
• precursor,
• phenomenon,
• force,
• control,
• contaminant,
• dna,
• issue,
• drug,
• opsonin,
• component,
• metal,
• opiate,
• stimulant,
• ligand,
• sterol,
• alteration,