NANOG and atrial fibrillation: Several reports have attributed features of pluripotency to cultured AF cells under standard culture conditions (namely, without culture factors that support pluripotency), including high telomerase activity [14], the embryonic stem cell markers Oct-4 [15,16], Nanog [17] and Sox2 [13,18], and the hematopoietic and embryonic stem cell marker c-Kit [19,20,21,22].