CRY1 and B-cell chronic lymphocytic leukemia: In support of this antitumorigenic effect of CRY absence or downregulation, it was found that in low-risk and slow-progressing chronic lymphocytic leukemias, Cry1 expression is silenced by aberrant CpG hypermethylation and that the methylation status of the Cry1 promoter could be used as a prognostic marker (51, 52).