In response to reports showing that cerebrospinal fluid (CSF) abnormalities were more common in individuals with syphilis and serum rapid plasma reagin (RPR) titers ≥1:32, or, in PLWH with peripheral blood CD4+ T cells ≤350/ul, the 2006 guidelines suggested consideration of LP in individuals who met these criteria [2]. The gene discussed is CD4; the disease is syphilis.