The four best-performing candidates from the test series (DSP, FZD8, KCNH2, and PPP1R14A) were further subjected to promoter methylation analyses in a validation series, which included additional NHL samples (n = 25) and healthy controls (bone marrow, tonsils, peripheral blood mononuclear cells and follicular hyperplasia samples, n = 42). Here, KCNH2 is linked to non-Hodgkin lymphoma.