A large part of these studies have proved this result, for instance, Rainero et al. (2005) reported that there was no correlation between the CLOCK gene 3092 T- > C (rs1801260) and CH in an Italian CH case-control sample (210 patients and 107 controls) [27], which is supported by subsequent studies of Zarrilli et al. (2015) and Cevoli et al. (2008) [24, 28]. Here, CLOCK is linked to cyclic hematopoiesis.