You will be shown an excerpt from a computer science scientific research paper, followed by a question about the paper. Please answer the question. Do not include any text in your response other than the answer.

Context: Alopecia, folliculitis, and psoriasis are some common causes of hair loss. There is a difference between regular hair fall and alopecia; the latter develops coin-sized bald patches all over the scalp area. Alopecia or patchy hair loss can be of different types. Androgenetic alopecia or male-pattern baldness (MPB) is the most common form of alopecia where the hairline starts to recede, following a pattern where the frontal and temple area are most affected. 70% of men and 40% of women get this type of hair loss and thinning issue [3]. According to Liu et al., MPB is an X-linked polygenic disease, and males are more genetically prone to develop baldness at a mature age [5]. Topical minoxidil solution thickens the hair by 50% [3]. On the other hand, Alopecia areata (AA) is an autoimmune disease affecting individuals irrespective of age and sex. Primarily affecting the scalp area, AA can also spread in the beard, eyelashes, and eyebrows. In this case, the body’s immune cells cannot recognize hair follicles as ‘self.’ Instead, they consider these follicles as ‘foreign,’ which ultimately causes the hair follicles to be targeted and destroyed by the immune cells. It is an example of a hereditary disease. The study from Benigno et al. reported that, in the US alone, 700,000 individuals suffer from AA [6]. This disease, if diagnosed early, might resolve spontaneously. In severe cases, topical corticosteroid or immune therapy is used.

Question: Why in the case of Alopecia areata the body's immune cell can't recognise hair follicle as 'self?
Alopecia areata (AA) is an autoimmune disease where the body’s immune cells cannot recognize hair follicles as ‘self.’ Instead, they consider these follicles as ‘foreign'. It is an example of a hereditary disease. But the paper didn't fully discussed why the cell can't recognise hair follicle as 'self'. Therefore the question cannot be answered fully.