Methods to control, or manipulate, melanocyte and keratinocyte cell death are disclosed. In particular, a method of preventing epidermal melanocyte cell loss due to injury in a vertebrate is disclosed. Also disclosed is a method of inducing hair growth in a vertebrate, a method of inducing hair color in a vertebrate, a method of inducing skin color in a vertebrate, a method of treating baldness in an individual, and a method of treating alopecia areata in an individual.

Methods of treatment or prevention of hyperproliferative diseases or pre-cancerous conditions affecting epithelial cells, such as psoriasis, vitiligo, atopic dermatitis, or hyperproliferative or UV-responsive dermatoses, hyperproliferative or allergically mediated diseases of other epithelia and methods for reducing photoaging, or oxidative stress or for prophylaxis against or reduction in the likelihood of the development of skin cancer, are disclosed.

Described are methods for treating hyperproliferative disorders, including cancers, by administering to the affected mammal (e.g., human) an effective amount of a composition comprising pTT or a composition comprising one or more oligonucleotides which share at least 50% nucleotide sequence identity with the human telomere overhang repeat. Methods of treatment or prevention of hyperproliferative diseases or pre-cancerous conditions affecting epithelial cells, such as psoriasis, atopic dermatitis, or hyperproliferative or UV-responsive dermatoses, hyperproliferative diseases of other epithelia and methods for reducing photoaging, or oxidative stress or for prophylaxis against or reduction in the likelihood of the development of skin cancer, are also disclosed.

Methods to control, or manipulate, melanocyte and keratinocyte cell death are disclosed. In particular, a method of preventing epidermal melanocyte cell loss due to injury in a vertebrate is disclosed. Also disclosed is a method of inducing hair growth in a vertebrate, a method of inducing hair color in a vertebrate, a method of inducing skin color in a vertebrate, a method of treating baldness in an individual, and a method of treating alopecia areata in an individual.

Methods for evaluating the risk of an individual to develop Alzheimer's disease using cultured neural crest-derived melanocytes are described. Also described are methods of therapy for Alzheimer's disease using peptides that bind to the neurotrophin receptor (p75.sup.NTR) and competitively inhibit the binding of .beta.-amyloid to the p75.sup.NTR.