The existence of links between the cell division cycle and the circadian clock has been recently discovered. In this research report, we perform a small in silico analysis of how mutations on the clock genes composing the mammalian circadian clock affect the phenotype of the cell cycle. For this purpose, we use a coupled model of the mammalian circadian clock and the mammalian cell cycle where the latter one is entrained by the former one via a common protein kinase WEE1. Our in silico experiments exploit the modeling environment BIOCHAM.