Analysing the results of real-time PCR
Please provide more information: fold-change relative to what?

If you did what I think you did (single control gene that you calculated fold change to of your gene of interest) I'd say this is the wrong approach. What you need is a set of genes which have similar expression levels across all your samples (controls and cases) to be able to compare your gene of interest to some common baseline. Selection of such genes should be the first step in the project, and it might be a good idea to use one of the established approaches - I recommend Jo Vandensompele's GeNorm (link to the paper) method. It goes like this: from a panel of potential control genes you select two or three that are most stably expressed across your experimental conditions, and then use these two-three control genes along with your gene of interest in a qRT-PCR. You then normalize the signal from your gene to a mean of the control genes.

It has been repeatedly shown that using a single control gene, even a so-called 'housekeeping gene' is misleading, because those genes do change their expression levels in some conditions. Also, using several control genes protects you against potential problems due to unequal amplification efficiency in different samples/groups. However, if you have multiple gene of interest, they all must have comparable amplification efficiency.