We immunoprecipitated endogenous CCDC188 from testis protein lysates of adult wild-type mice using our homemade CCDC188 antiserum. No CCDC188 protein was identified in protein lysates in which mouse IgG was added. Thus, testis protein lysates added to mouse IgG were utilized as the negative control. A high-throughput technology, LC/MS–MS (MS), was applied to identify the candidate interacting proteins of CCDC188.