The function of SPOCD1 (SPOC domain containing 1, ENSG00000134668) is as follows. Protein adapter that acts as an essential executor of PIWIL4- piRNA pathway directed transposon DNA methylation and silencing in the male embryonic germ cells (PubMed:38359823). Recruited to young transposons, which are specifically marked with histone H3 trimethylated at both 'Lys-4' and 'Lys-9' (H3K4me3K9me3), via its association with SPIN1 chromatin reader, and associates with the de novo DNA methylation machinery and repressive chromatin remodeling complexes (By similarity). Following this, PIWIL4 engages with nascent transposable element transcript to direct piRNA-directed DNA methylation. Not required for piRNA biosynthesis (By similarity). .