To identify the potential interaction partners of PRSS37, three testis lysates of Prss37E/+ mice (PRSS37-EGFP knock-in heterozygous mice) and three testis lysates of pAcr-EGFP transgenic mice were immunoprecipitated using anti-GFP mAb magnetic beads. The GFP-IP products of six samples from two groups were subsequently analyzed by mass spectrometry (MS) to identify differentially immmunoprecipitated proteins (DIPs) in the PRSS37-EGFP group. Proteins detected in pAcr-EGFP group were used as negative controls to exclude the endogenous proteins and polypeptides that interact nonspecifically with the anti-GFP mAb magnetic beads.