Fig. 1From: Human amniotic mesenchymal stem cells improve ovarian function in natural aging through secreting hepatocyte growth factor and epidermal growth factorHuman amniotic mesenchymal stem cells (hAMSCs) improve the follicle numbers in the ovaries of a natural ovarian aging (NOA) mouse model at four stages. a The number of primordial follicles was counted over 4 weeks after hAMSC transplantation. b The number of primary follicles was counted over 4 weeks after hAMSC transplantation. c The number of secondary follicles was counted over 4 weeks after hAMSC transplantation. d The number of antral follicles was counted over 4 weeks after hAMSC transplantation. All the experiments were repeated three times; the error bars indicate SD. **p < 0.01, ***p < 0.001, versus the NOA group. PBS phosphate-buffered saline Back to article page