clipped from: scienceblogs.com Us dudes are always accused of thinking with our dicks. Perhaps it's because the genes expressed in our brains are similar to those expressed in our 'nads:
Among the 17 tissues, the highest similarity in gene expression patterns was between human brain and testis, based on DDD and clustering analysis. Genes contributing to the similarity include ribosomal protein (RP) genes as well as genes involved in transcription, translation and cell division.