PtdIn(3,4)P2 can also be generated by class II PI3Ks, and PIP2 can function as a second messenger like PIP3 to recruit pleckstrin-homology(PH)-domain-containing proteins, such as AKT.

• 不需要激活:有关一点下面的一段中可知PIP2可由II型PI3K介导产生，是否是激活我不敢断定，因为未看到原文。至少可以肯定PIP2也可以作为第二信使来传递信号。