Both factors were independently associated with 12 and 14 expression traits respectively. Inspection of the genes listed in Table 6 shows that several of them, including CX3CR1, CD209, CLEC10A, FCER1A, FCGBP, C1RL, C1QB, CD36, ADM and VSIG4, encode proteins involved in the differentiation or maturation of immunity-related cells and in host defence [32]–[38]. We may speculate that the variability of expression of these genes is the consequence of an already present heterogeneity of monocytes [39], [40] or reflects a particular transcription pattern that prefigures future functional changes. The example of CX3CR1 which was positively associated with both BMI and CRP is particularly interesting as this gene encodes the fractalkine receptor whose role is essential in the migration of monocytes to sites of inflammation and injury, especially in atherosclerotic lesions [41].
