instruction:
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.
question:
 We have previously reported that BMP - 2 inhibited the growth of HS - 72 mouse hybridoma cells by inducing p21 ( CIP1 / WAF1 ) expression .
answer:
BMP - 2


question:
 Furthermore , supernatant from Dx - treated CTL contained a nondialyzable factor which inhibited DNA synthesis and cell growth of CTL clones induced by IL 2 .
answer:
IL 2


question:
 The activation of this signaling pathway requires functional CD4 receptors and is independent of binding to CXCR4 .
answer:

CD4 receptors