You gain the following benefits.
When you use the Medical Intuition benefit of your Mark of Healing feat, you can roll 1d6 instead of 1d4.
You can now use the Healing Touch benefit of your Mark of Healing feat to cast Cure Wounds without using a spell slot a number of times equal to your Proficiency Bonus, and you regain all expended uses when you finish a Long Rest. Additionally, when you cast Cure Wounds and roll dice to determine the number of Hit Points restored, you can treat any 1 or 2 on a roll as a 3.