# infection > A mutation testing framework for PHP. > More information: . - Analyze code using the configuration file (or create one if it does not exist): `infection` - Use a specific number of threads: `infection --threads {{number_of_threads}}` - Specify a minimum Mutation Score Indicator (MSI): `infection --min-msi {{percentage}}` - Specify a minimum covered code MSI: `infection --min-covered-msi {{percentage}}` - Use a specific test framework (defaults to PHPUnit): `infection --test-framework {{phpunit|phpspec}}` - Only mutate lines of code that are covered by tests: `infection --only-covered` - Display the mutation code that has been applied: `infection --show-mutations` - Specify the log verbosity: `infection --log-verbosity {{default|all|none}}`