4] Human genes: SRY, sex-determining region Y; TSPY1, testis-specific protein, Y-linked
1; TSPY2, testis-specific protein, Y-linked
2; and TSPY3, testis- specific protein, Y-linked
3; NQO1, NAD(P)H dehydrogenase, quinone 1.
Specifically, men with haplogroup I were shown to have decreased expression of 2 genes: the ubiquitously transcribed tetratricopeptide repeat, Y-linked
gene (UTY) and protein kinase, Y-linked
, pseudogene (PRKY) in macrophages.
For example, the use of a detection target, DYS14 (1, 3), which is a member of a multicopy Y chromosome-specific gene, TSPY1  (testis specific protein, Y-linked
1), has produced a higher sensitivity in detecting circulating donor-derived DNA than when the single-copy gene SRY (sex-determining region Y) is used (2).