Actually, the CIS1/CIS2 subtypes can be characterized from different perspectives: (1) at the phenotypic level, CIS1 and CIS2 show notable differences in several key osteoporosis indices, e.g., BMD, BTMs and response to calcium supplementation; (2) at the molecular level, CIS1 and CIS2 have significant differences in candidate signatures from different omics data, e.g., the epigenetic difference in the regulation of the calcium pathway; (3) in terms of fracture risk, CIS1 had a lower fracture rate compared to CIS2 according to the 4-year follow-up results. Here, SOCS2 is linked to osteoporosis.