The synaptonemal complex protein 1 (SCP-1), also known as SYCP1(A), SYN1(I) and HOM-TES-14, is a protein product of human chromosome 1p13-p12. SCP-1 is a major component of the transverse filaments of synaptonemal complexes and functions by pairing homologous chromosomes during meiotic prophase in spermatocytes, which is an essential step for the generation of haploid cells in meiosis I. SCP-1 is expressed in the testis, adult brain, some malignant gliomas, breast, renal cell and ovarian cancer. SCP-1 is known to be selectively expressed during the meiotic prophase of spermatocytes and shows cell cycle phase-independent nuclear expression in cancer cells.