The major methyltransferases are: COMT (catechol-O-methyltransferase) : inactivates catecholamines (dopamine, norepinephrine, epinephrine), catechol estrogens, and catechol drugs (L-DOPA) R HNMT (histamine N-methyltransferase) : the primary intracellular histamine degradation enzyme in the brain and peripheral tissues R INMT (indolethylamine N-methyltransferase) : methylates tryptamine, serotonin, and other indoleamines R NNMT (nicotinamide N-methyltransferase) : methylates nicotinamide (vitamin B3) and other pyridines R TMT (thiol S-methyltransferase) : S-methylates thiol drugs (captopril, D-penicillamine) and thiol metabolites R TPMT (thiopurine S-methyltransferase) : methylates thiopurine drugs (azathioprine, 6-mercaptopurine) used in autoimmune disease and cancer R Methylation capacity depends on the methylation cycle: methionine to SAM-e to SAH to homocysteine, recycled back to methionine by methionine synthase (B12-dependent) or BHMT (betaine-dependent)

They should also be instructed about signs and symptoms that warrant dose adjustment or medical evaluation, including severe gastrointestinal side effects or other unusual symptoms that may indicate adverse reactions, as determined relevant by the prescribing clinician
Prolonged or severe diarrhoea could potentially lead to deficiencies in vitamins, minerals, and electrolytes
17 While ERAD was previously thought to be associated with PQC, which safeguards protein maturation, recent studies have demonstrated that ERAD also regulates the abundance of folding-competent proteins as a means to fine-tune key physiological processes, suggesting that ERAD constitutively functions to ensure both protein fidelity and abundance