Platelet activation has been described in patients with congestive HF versus healthy controls as increased whole blood aggregation and increased markers of platelet activation markers, such as soluble P‐selectin (CD62P, SELP), β‐thromboglobulin [cleavage product from platelet basic protein (PPBP)] and CD40L (CD40LG), and a higher MPV, as reviewed by Mentz et al. 25Interestingly, patients with congestive HF tend to have similar levels of platelet markers compared with patients with coronary disease without HF.25 The gene discussed is CD40LG; the disease is hydrops fetalis.