Figure 4. Age- dependent HOXA5 mRNA decline. mRNA expression levels of DUSP3, HOXA5 and RYR1 are demonstrated in young and old subjects. While there was no significant difference in mRNA expression demonstrated for DUSP3 and RYR1, HOXA5 mRNA levels are significantly down-regulated in monocytes of old blood donors. Detection of mRNA expression was performed by qRT-PCR on total cellular RNA prepared from monocytes. Error bars denote SEM (n = 30, average age: 23.0 yrs and 81.1 yrs, respectively).