Toward that end the expression of β-actin (BA), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), β2-microglobulin (B2M) and RNA polymerase II polypeptide A (PolR2A) in PBMCs from war veterans with current or lifetime PTSD, without PTSD (trauma controls), and from healthy non-traumatized subjects was studied by the TaqMan Real-time PCR method. Here, B2M is linked to post-traumatic stress disorder.