Together, Jurkat–SMPU reporter cell clones 21 and 29 stimulated with PHA-P and IL-2 were identified as a suitable cell culture system to be used in infection experiments due to their Tax-responsiveness (Figure 2A, Figure S1 and Figure 3B,D,E), high efficiency in activating GFP expression (Figure 3A,B,E), and limited background activity (Figure 4A,B). Here, IL2 is linked to infection.