Westra et al. performed the largest eQTL meta-analysis so far in non-transformed peripheral blood samples of 5311 European healthy individuals with replication in 2775 European individuals [24]. Another eQTL study [30] which were performed to investigate the genetic architecture of gene expression (GAGE) in peripheral blood in 2765 European individuals was used to verify the results. It is widely accepted that eQTL effect in blood tissue can be a proxy for eQTL effects in most relevant tissues for various traits or diseases [22,24]. Particularly, there are several types of cells such as peripheral blood monocytes (PBMs) and B and T lymphocytes that are related to bone metabolism [31]. For example, PBMs have been well established as a working cell model for studying gene expression patterns in relation to osteoporosis risk in vivo in humans [32]. PBMs may act as precursors of osteoclasts since they can differentiate into osteoclasts [33], and they express different cytokines which are important for osteoclast differentiation, activation, and apoptosis [32,34]. B lymphocytes, an important cell type of the immune system, express/secrete factors involved in osteoclastogenesis, such
