taking into account results of others indicating a possible involvement of the queuosine modification in differentiation of eukaryotic cells , we hypothesize that the queuosine defect may develop at an early stage of carcinogenesis ( i.e. , during the promotion phase ) and be directly involved in abnormalities of mitochondria which have been observed frequently in transformed cells and tumors .
C0007589
differentiation
C0007634
cells