How can I find out if my gene of interest is expressed in a specific tissue type or cell line?

Visit the Unigene page at NCBI and retrieve your gene (transcript variant) of interest. In the 'Gene Expression' section on this page you will find a list of tissue types in which the specific transcript is expressed. You can also access the gene expression profile with information on the expression levels in different tissues. Detailed information on expression levels in various cell lines can be accessed at the GEO Profile link on the same page.