CD4 and synovial sarcoma: qRT-PCR and western blotting were performed to evaluate the expression of KLHL42 and showed a significantly higher expression of KLHL42 in CD4+ T cells from the SS patient (mainly malignant cells), HH cells (derived from a late-stage aggressive MF patient), and Hut78 cells (derived from a Sézary patient) compared to CD4+ T cells from advanced-stage MF patients, PE patients, and HCs [33] (Fig. 6A, B).