Microsoft Knowledge Base Article 883397 contains the following introduction:

This article describes how to make the Cluster service dependent on the Microsoft iSCSI Initiator service (MSiSCSI).

In a server cluster that uses only iSCSI technology for the shared storage device, you must make the Cluster service dependent on the Microsoft iSCSI Initiator service. This is to make sure that the Microsoft iSCSI Initiator service starts before the Cluster service starts.

Note If the server cluster is not a pure iSCSI environment, you do not have to set this dependency. For example, if the server cluster uses other technologies together with iSCSI for the shared storage device, you do not have to set this dependency. A mixed server cluster might use iSCSI technology together with another technology, such as fibre channel.