TASK DEFINITION: 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.
PROBLEM:  Positive and negative regulation of granulopoiesis by endogenous RARalpha .

SOLUTION: endogenous RARalpha

PROBLEM:  Expression of oestrogen and progesterone receptors by mast cells alone , but not lymphocytes , macrophages or other immune cells in human upper airways .

SOLUTION: progesterone receptors

PROBLEM:  Persistent activation of the immune system is one of the hallmarks of HIV - 1 infection .

SOLUTION:
HIV - 1