Final answer:
Pemphigus vulgaris most likely affects the epithelial tissue and specifically the desmosomes, which hold epithelial cells together. This results in weakened epithelial tissue and the formation of painful blisters and sores.
Step-by-step explanation:
Pemphigus vulgaris is an autoimmune disease that affects the epithelial tissue the most.
Epithelial tissue is a type of tissue that serves primarily as a covering or lining of body parts, protecting the body. It also functions in absorption, transport, and secretion.
In pemphigus vulgaris, the immune system mistakenly attacks the desmosomes, which are specialized junctions that hold epithelial cells together. As a result, the epithelial tissue becomes weakened, leading to the formation of painful blisters and sores.