Platelet CD40L expression was 7.63 ± 1.37% in HC, 16.08 ± 3.28% in early RA patients and 6.99 ± 1.15% in RA patients following a 3-month treatment with MTX (p = 0.0459 RA vs HCs and p = 0.0148 post- vs pre-MTX) (Fig. 1E), with a trend similar to that of sVCAM-1. Here, CD40LG is linked to rheumatoid arthritis.