One of the main things that we use cell culture or maintenance of cells outside the body for is to make more copies of cells.

我们培养细胞,或者体外维持细胞的重要步骤,就是复制更多的细胞

耶鲁公开课 - 生物医学工程探索课程节选

The main effector cells in cell mediated immunity, the cells that do the main business are called T-cells.

细胞免疫中的主要效应细胞,即发挥主要作用的细胞是T细胞

耶鲁公开课 - 生物医学工程探索课程节选