Resident tissue macrophages (RTMs) have a broad spectrum of immune- and non-immune-related tissue-supporting activities. The roots of this heterogeneity and versatility are only beginning to be understood. Here, we propose a conceptual framework for considering the RTM heterogeneity that organizes the factors shaping RTM identity within four cardinal points: (1) ontogeny and the view that adult RTM populations comprise a defined mixture of cells that arise from either embryonic precursors or adult monocytes; (2) local factors unique to the niche of residence, evolving during development and aging; (3) inflammation status; and (4) the cumulative effect of time spent in a specific tissue that contributes to the resilient adaptation of macrophages to their dynamic environment. We review recent findings within this context and discuss the technological advances that are revolutionizing the study of macrophage biology.

居民组织巨噬细胞（RTM）具有广泛的免疫和非免疫相关组织支持活动。这种异质性和多功能性的根源才刚刚开始被理解。在此，我们提出了一个概念框架，用于考虑RTM异质性，该异质性组织了在四个基本点内影响RTM身份的因素：（1）个体发育，并认为成年RTM群体包含由胚胎前体或成年单核细胞产生的确定的混合物; （2）居住地利基所特有的局部因素，在发展和老化过程中不断发展；（3）炎症状态；（4）在特定组织中所用时间的累积影响，有助于巨噬细胞适应其动态环境。