The present invention is related to an activity regulator which is a means for regulating activity of CD300b dependent phagocytosis, and further related to an agent for treating or preventing diseases or disorders associated with the activity, wherein the activity regulator comprises CD300a binding materials and regulates CD300b dependent phagocytic signal in macrophages.本發明係關於一種活性調節劑，該活性調節劑係用以調節CD300b依賴性吞噬作用的活性之手段，本發明進一步關於一種用以治療或預防該活性所涉及的疾病或病狀之藥劑，該活性調節劑包含CD300a結締性物質，並且調節巨噬細胞中之CD300b依賴性吞噬訊號。
