Fisher test was adopted to analyze the distribution variation of 12 cell subpopulations between osteoporosis and osteoarthritis, as the cutoff of FC>4 or FC<0.25 andp < 0.05, and subpopulations of CD45- BM-MSCs_6 and CD45+ BM-MSCs_5 were selected as vital for next analysis (Table 1). Here, PTPRC is linked to osteoporosis.