One study reported serum interleukin-2 receptor (IL2R) levels to be increased in antipsychotic-naive or typical antipsychotic-medicated schizophrenia patients with TD versus those without (Rapaport and Lohr, 1994), while another study reported IL2 levels to be decreased in chronic-medicated schizophrenia patients with TD compared to those without (Liu et al., 2012). Here, IL2RA is linked to schizophrenia.