DKK1 and osteoporosis: Importantly, osteocytes can serve as endocrine cells to synthesize and express important regulatory molecules including RANKL, Dickkopf‐1 (DKK1) and sclerostin (SOST)233, 234, 235 and thus participating in bone resorption and formation regulation by coupling osteoclast and osteoblast activities.6 Studies have shown that fatty acids such as PA and PGE2 have noteworthy influences on osteocyte metabolism, which might provide novel therapeutic strategies for bone diseases like osteoporosis.