The other interesting cluster of genes that were upregulated in PD patients three years after the diagnosis were related to T-cell receptors: exon 1 and exon 4 from the TRDC-201 (T cell receptor delta constant), exon 2 from the TRDV2 (T cell receptor delta variable 2), and exon 3 from the AE00061.37 that is a transcript TRD-AS1-207 of the gene TRD-AS1 (T cell receptor delta locus antisense 1). Here, TRDV2 is linked to Parkinson disease.