Interleukin 15 (IL-15) is a 14-15 kDa polypeptide that belongs to the 4 alpha-helix-bundle family of cytokines and was originally discovered due to its T cell proliferative activity. It utilizes the signal-transducing beta/gamma polypeptides of the IL-2 receptor complex, thus sharing many biological activities with IL-2, in addition to its high-affinity private receptor subunit IL-15R alpha. Ac...

A great advance in physics came when it was realized that it was better to think about motion in empty space rather than starting with what happen in the “real world” with gravity pulling things downwards, friction slowing things down, etc. First, that the laws of physics should be the same at one point as at another, i.e. that they are translation invariant, and also from one day to another, i...