IL15 and melanoma: In the presence of IL-2 and IL-15 but in the absence of HMBPP, day 14 γδT cells continued to proliferate at variable levels (zero to sixfold) during subsequent 7 days cultures, which may reflect the considerable variation in activation states, as evidenced by the expression of CD69 [75–86 and 24–96% in γδT cells from healthy individuals (n = 5) and melanoma patients (n = 9), respectively] and CD25 [2–36 and 2–76% in γδT cells from healthy individuals (n = 5) and melanoma patients (n = 9), respectively].