Temperature-sensitive alleles are an example of conditional alleles; at the permissive temperature, the gene has normal function, whereas at the restrictive temperature, the gene has mutant function. You are studying the E2F pathway and you obtain a temperature-sensitive CDK4 mutant. At the permissive temperature, CDK4 functions normally. At the restrictive temperature, CDK4 is non-functional. Would you expect cells to continue growing or stop dividing when at the restrictive temperature? Explain your answer.