ZAP70 and systemic lupus erythematosus: In the TCR signaling pathway, we observed lower expression of several genes like CBLB, PPP3CC, NFKB1, CD3E, and ZAP70. Recently, a study by Matsuo et al. revealed that a genetic mutation in ZAP70 resulted in the TCR signaling defect which followed by T follicular helper (Tfh) cell development and the manifestation of lupus-like systemic autoimmunity [56].