PDILT (protein disulfide isomerase like, testis expressed) is a redox-inactive chaperone protein that plays a critical role in spermatogenesis and male fertility 1. Unlike other PDI family members, PDILT lacks catalytic cysteines required for oxidoreduction reactions but retains chaperone activity, helping fold spermatogenesis-specific proteins in postmeiotic male germ cells 12. Structurally, PDILT adopts a compact L-like crystal structure and extended chain-like solution structure, with hydrophobic regions crucial for substrate recognition 2. The protein forms tissue-specific chaperone complexes with calmegin in the endoplasmic reticulum and requires its C-terminal tail for suppression of protein aggregation 12. The substrate-binding b' domain contains a conserved hydrophobic pocket that preferentially binds exposed aromatic residues in protein substrates 3. Beyond its reproductive function, PDILT has emerged as clinically significant through genome-wide association studies, where variants in the UMOD-PDILT locus are associated with urinary uromodulin levels, kidney function, and chr16 kidney disease progression 456. These findings suggest PDILT may influence kidney physiology beyond its established role in male fertility, though the mechanistic basis for this association remains unclear.