Furthermore, another relevant finding of this study is the high prevalence of X-linked forms, which are expected to account for an inconsiderable part of the genetic forms (Smith et al., 2005) and that have been detected in three cases of both dominant and recessive X-linked NSHL, involving SMPX and POU3F4 genes. The gene discussed is POU3F4; the disease is nodular sclerosis classical Hodgkin lymphoma.