Accordingly, the NK cell killing activity in presence of TBs reached a maximum of cytotoxic average value of 33.2 ± 5.1% (E/T: 1:1) and 55.2 ± 8.8% (E/T: 5:1) with IL-2-cultured NK cells expanded for 10–14 days compared to significant lower cytotoxic levels of untreated NK cells [24.8 ± 9.4% (E/T: 1:1) and 26.8 ± 5.0% (E/T: 5:1)] (Figure 1B). The gene discussed is IL2; the disease is Townes-Brocks syndrome.