Serum starvation was used in the creation of Dolly and was believed essential to the success of nuclear transfer [1]. Serum starvation induces quiescence of cultured cells, and arrests them at the cell cycle stage of G0. Most laboratories that have succeeded with nuclear transfer have utilized a serum starvation treatment. However, there is a debate as to whether inducing quiescence is required for successful nuclear transfer. Cibelli et al. [52] proposed that G0 was unnecessary and that calves could be produced from cycling cells. In his study, actively dividing bovine fibroblasts were used for nuclear transfer and four calves were born from 28 embryos transferred to 11 recipients. Because 56% of cycling cells in that study were in G1 stage, it is likely that all cloned animals produced in this study were from donor cells at G1 stage. Cells at G2, S or M would not be expected to generate cloned animals in this study because they are incompatible with the recipient oocytes used. This study demonstrated that cells at G1 stage can produce live cloned animals and G0 induction is not essential.