The Google zone where the computation is executed in Compute Engine VMs. Multiple zones can be provided separating them by a comma. Default (`europe-west2-c`).
Please refer to the [Google Cloud](https://cloud.google.com/life-sciences/docs/tutorials/nextflow) and [Nextflow](https://www.nextflow.io/docs/latest/google.html#cloud-life-sciences) documentation which describe how to setup the Google Cloud environment.