MNCs from the peripheral blood (PBMCs) of three DKC patients (Patient #1, #2 and #3, Table 1, Figure 1A,B) and one healthy donor were stimulated with phytohemaglutinin (PHA) and interleukin-2 (IL-2) in order to expand the T-lymphocyte fraction. Here, IL2 is linked to dyskeratosis congenita.