In this article, we revealed the signaling mechanism of 2B4 in T cells utilizing an imaging system and confirmed that the features of 2B4 are commonly identified in 2B4.ζ-CAR, in which the intensity of SAP expression may be intentionally used to manipulate tumor-targeting cytotoxicity and proinflammatory cytokine production to an optimal degree. The gene discussed is SH2D1A; the disease is neoplasm.