Answer:
Macrophages identify and phagocytize RBCs that have attained a critical age (120 days in humans and 60 days in mice) in a process known as erythrophagocytosis [4–6]. In hypoxia, fibroblasts increase the release of Epo, thus accelerating the production of new cells and boosting the population of RBCs [7,8].
Explanation:
