Analysis of the 88 cell population-based bone modeling publications in Tables 1-4 reveals that roughly a third (30 of 88) mention or model estrogen. Of these 30 models, half capture estrogen effects in their mathematical model, while the other half only mention estrogen briefly. Most models that mention estrogen cite evidence that estrogen deficiency is involved in osteoporosis or modulates bone remodeling . The remaining articles that mention estrogen acknowledge that estrogen is not incorporated into their model or that integration of estrogen is an opportunity for future models .