Given the task definition and input, reply with output. In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

 Our results suggest that the eventual appearance of CD80 on recently activated CD86 + APC is important for the superinduction of IL - 2 production and to support vigorous T cell proliferation .

IL - 2