Normally, the liver and kidneys produce a tiny hormone called thrombopoietin which binds to hematopoietic cell receptors.

正常情况下，肝脏和肾脏会合一种叫做促血小素的激素，可以与造血受体结合。

Cells can also develop mutations in the thrombopoietin receptor, MPL, or in the chaperone protein, Calreticulin or CalR.

的促血小素受体（MPL）或伴侣蛋白/钙网蛋白（CalR）也可以发突变。

Now, when there's a genetic mutation in CalR, the signalling pathway remains active all the time, and that means that platelets keep getting produced even in the absence of thrombopoietin.

在CalR发基因突变后，信号通路处于持续激活状态，这就意味着即使没有促血小素，血小也会持续。