Again, this decrease is expected as ALP is a by-product of osteoblastic activity, highly expressed in pre-osteoblasts and osteoblasts but not expressed by transitional cells and osteocytes.18 At the mRNA level (Fig. 3c), overall differences between 2D hOB and hOBMT were observed for COL1, SOST (*), and RANKL (****), with none observed for ALP and AR. In PCa-AD, RANKL, and AR were lightly upregulated in 2D (3.7-fold, 1.6-fold) although this was not observed for hOBMT, highlighting the differences between 2D and 3D settings. This evidence concerns the gene AR and Alzheimer disease.