According to the categorized calcidiol levels, SLE patients with calcidiol deficiency showed 3.58-fold higher VDR expression compared to SLE patients with insufficiency; in the CS with calcidiol insufficiency, 1.36-fold lower VDR expression was observed (2ΔΔCq = 0.73), whereas CS with deficiency showed 3.96-fold higher VDR expression, compared to CS with calcidiol sufficiency (Figure 4c). Here, VDR is linked to systemic lupus erythematosus.