In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

Let me give you an example: Sox - 4 is important for very early B - cell differentiation , while TCF - 1 / LEF - 1 play a crucial role in early thymocyte development
The answer to this example can be: TCF - 1
Here is why: The gene, TCF - 1 has been tagged as protein since it plays a crucial role in early thymocyte development.

OK. solve this:
Finally , the conservation of the two residues most sensitive to mutations ( Y949 and Y953 ) in TM11 , and in the homologous TM5 , of all mammalian P - gps and also in other ABC transporters , suggests that these residues and domains may play an important role in structural as well as mechanistic aspects common to this family of proteins .
Answer:
ABC transporters