Researchers are exploring the use of label-free multiphoton imaging flow cytometry, a technique that allows for the examination of cells without the need for labels. This approach is being applied to various types of cells, including immune cells, bacteria, and brain cells, to study their characteristics and functions. The method appears to involve the use of multiphoton and optical imaging, as well as deep learning and other technologies, to enable high-resolution and real-time analysis of live cells.