Which of the following statements is not correct?

• Innate immunity is an example of non-specific immunity. Conversely, acquired or adaptive immunity is an example of highly specific immunity.
• Macrophages, or the big-eaters are special types of modified WBCs which have the potential to engulf other cells and microbes (phagocytosis).
• The flower tops, leaves and the resin of Cannabis plant are used in various combinations to produce marijuana, hashish, charas, and ganja, all of which are classified as cannabinoids. They interact with cannabinoid receptors present mainly in the brain.
• Opioids are substances that, when reaching opioid receptors, have effects similar to those of morphine (Heroin is an opioid drug made from the acetylation of morphine), often used as medicines because they contain chemicals that relax the body and can relieve pain, though some opioids can be used to treat coughing and diarrhoea. The opioid drugs which bind to their specific opioid receptors present in our central nervous system and gastrointestinal tract.