Null cells意思

"Null cells" is not a term commonly used in biology or medicine. However, there is a term "null cell" that refers to a type of lymphocyte, which is a type of white blood cell involved in the immune system.

In the context of lymphocytes, a null cell is a lymphocyte that does not express any of the typical markers used to classify them into T cells, B cells, or natural killer (NK) cells. T cells, B cells, and NK cells are the three main types of lymphocytes, and they are typically identified by the presence of certain surface proteins or markers.

Null cells were originally described as a small population of lymphocytes that lacked the markers used to identify T cells (such as CD3), B cells (such as CD19 or CD20), and NK cells (such as CD56 or CD57). These cells were thought to represent a distinct population of lymphocytes, but their exact nature and function are still not well understood.

It's important to note that the term "null cell" is somewhat outdated and not widely used in modern immunology. The lack of specific markers on a lymphocyte does not necessarily mean that it is a unique cell type, as it may simply be an immature or activated cell that does not express the usual markers at the time of analysis.

If you are referring to a different context, such as computer science or statistics, the term "null" can refer to a value that is empty or not applicable, but this is not relevant to the biological definition of lymphocytes.