In the case of CD4+ T cells, CD8+ T cells, and NKT-like cells, there is a significant upregulation of the PD-1 co-inhibitory receptor in patients with early-onset preeclampsia compared to healthy individuals, while its ligand PD-L1 is significantly elevated on the cell surface by NKT-like cells only. The gene discussed is CD4; the disease is preeclampsia.