Nagashima-type palmoplantar keratosis, also known as Nagashima palmoplantar keratosis, is a hereditary palmoplantar keratosis in which the causative gene (SERPINB7) was first named and discovered in Japan. It is mainly characterized by erythema and thickening of the skin on both hands and feet, accompanied by whitening and swelling of the palmoplantar keratin when exposed to water, and excessive sweating of the hands and feet. The sweating of the feet is usually secondary to fungal infection, and some patients also have erythema and keratosis of the skin on the elbows and knees. This disease is an autosomal recessive disorder caused by mutations in the SERPINB7 gene, and this disease has a high incidence in China and Japan due to the high percentage of Chinese and Japanese carrying the SERPINB7 causative gene (up to 3%), and as reported in our paper study, this disease is probably the most common hereditary palmoplantar keratosis in our national population. This article, published in the Journal of Investigative Dermatology, the top international journal in dermatology, is the first in China to identify the causative gene and the source of the mutation loci in seven cases of hereditary long-island palmoplantar keratosis in our research group. The understanding of long-island palmoplantar keratosis can solve the most important question in the minds of many patients: Will our palmoplantar keratosis be inherited? Will our children have dental abnormalities in the future? Will the child have abnormal nails? Will our children develop dental abnormalities, nail abnormalities, or even fracture and contracture of the fingers and toes? This article can give you some of the answers. If you still have other questions, you can communicate with me.