CCIN is a basic protein of the sperm head cytoskeleton. This protein contains kelch repeats and a BTB/POZ domain and is necessary for normal morphology during sperm differentiation.The protein encoded by this gene is a basic protein of the sperm head cytoskeleton. This protein contains kelch repeats and a BTB/POZ domain and is necessary for normal morphology during sperm differentiation. This gene is intronless.