The transfer factor of the lung for carbon monoxide (T_LCO) and spirometry are our two most valued tests in functional assessment. The understanding of the physiology underpinning T_LCO (or D_LCO) owes much to Robert Forster's research, including the formulation of the Roughton–Forster equation [1], the topic of this editorial. His other research involved oxygen and CO₂ exchange, the role of carbonic anhydrase, and gas exchange in general. Robert (Bob) had a great sense of humour, and was delightful company (figure 1). He remained interested and engaged in the T_LCO until a few months before his death in September 2021.

一氧化碳的肺转移因子 ( T _LCO ) 和肺活量测定是我们在功能评估中最有价值的两项测试。对支持T _LCO（或D _LCO ）的生理学的理解很大程度上归功于 Robert Forster 的研究，包括本社论主题 Roughton-Forster 方程 [1] 的公式化。他的其他研究涉及氧气和 CO ₂交换、碳酸酐酶的作用以及一般的气体交换。罗伯特 (Bob) 很有幽默感，与人相处愉快（图 1）。直到 2021 年 9 月去世前几个月，他一直对T _LCO感兴趣并参与其中。