TH and in situ carcinoma: Enclosed are data regarding mRNA levels for dopaminergic receptors (DR), adrenoceptors (AR) and tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of catecholamines, found in peripheral blood mononuclear cells (PBMC) (Table 1, Table 2) and in CD4+ T effector (Teff) cells (Table 3) and regulatory (Treg) cells (Table 4) from subjects with clinically isolated syndromes (CIS), which is a first, usually recovering, episode of neurological disturbance(s) suggestive of multiple sclerosis (MS).