e, because the Istio CA certificate (<code>ca-cert.pem</code>) is not set as the workloadsâ€™ root certificate (<code>root-cert.pem</code>), the workload cannot validate the workload certificates directly from the root certificate. The workload needs a <code>cert-chain.pem</code> file to specify the chain of trust, which should include the certificates of all the intermediate CAs between the workloads and the root CA. In this example, it only contains the Istio CA certificate, so <code>cert-chain.pem</