Testicular lysates from WT and Cfap91-BioID2-3xFLAG mice were immunoprecipitated by an anti-FLAG antibody to determine CFAP91-interacting proteins. Cauda epididymal spermatozoa were isolated from WT and Cfap91-BioID2-3xFLAG mice and incubated with biotin (+) medium. Then, biotinylated proteins were pulled down by streptavidin to determine the proximate proteins of CFAP91.