CD2 and pulmonary fibrosis: This is especially true for patients who test negative for anti-citrullinated protein antibodies.[41] The CD247 molecule, also known as T-cell surface glycoprotein CD3 zeta chain, has potential as a disease severity and prognostic biomarker for Idiopathic pulmonary fibrosis among T-cells.[42] The glycoprotein CD2 is expressed primarily on T and NK cells and serves as a costimulatory receptor.[43] In summary, these 9 genes are correlated with immune responses or with KLRB1, which requires further studies to explore the interaction of these genes with KLRB1 in TGCT.