Time evolution of protein, protein 2, protein 3 and miRNA is illustrated in the presence of low (V
SMIRNA = 0.1), intermediate (V
SMIRNA = 0.18) and high (V
SMIRNA = 0.25) level of miRNA in panels A, B, and C, respectively. An appropriate level of miRNA creates a proper time-delay that favors the occurrence of sustained oscillations (see panel B). An elevated level of miRNA strongly represses the level of the different proteins, which abolishes the occurrence of sustained oscillatory behavior (panel C). Even if proteins 2 and 3 are not directly involved in the core of the oscillator, the model predicts that they can oscillate in phase with the protein directly involved in the negative feedback loop of the oscillator. Parameter values are as in Table 2 with n = 4.