PTK2B（protein tyrosine kinase 2 beta），癌症关联基因，基因ID：2185，该基因编码胞质蛋白酪氨酸激酶，参与钙诱导的离子通道调节和MAP激酶信号通路的激活。编码蛋白可能是神经肽激活受体或增加钙通量的神经递质与调节神经元活性的下游信号之间的一个重要信号中间产物。编码蛋白在细胞内钙浓度增加、烟碱乙酰胆碱受体活化、膜去极化或蛋白激酶C活化的作用下迅速进行酪氨酸磷酸化和活化。这种蛋白已被证明能结合CRK相关底物、肾囊肿蛋白、与FAK相关的GTPase调节因子和GRB2的SH2结构域。编码蛋白是蛋白酪氨酸激酶fak亚家族的成员，但与其他亚家族的激酶缺乏显著的序列相似性。四个转录变异体编码两种不同的亚型已被发现这个基因。This gene encodes a cytoplasmic protein tyrosine kinase which is involved in calcium-induced regulation of ion channels and activation of the map kinase signaling pathway. The encoded protein may represent an important signaling intermediate between neuropeptide-activated receptors or neurotransmitters that increase calcium flux and the downstream signals that regulate neuronal activity. The encoded protein undergoes rapid tyrosine phosphorylation and activation in response to increases in the intracellular calcium concentration， nicotinic acetylcholine receptor activation， membrane depolarization， or protein kinase。