[apcu_store](<http://php.net/manual/de/function.apcu-store.php>) can be used to store, [apcu_fetch](<http://php.net/manual/de/function.apcu-fetch.php>) to retrieve values:

$key = 'Hello';
$value = 'World';
apcu_store($key, $value);
print(apcu_fetch('Hello')); // 'World'