PROCA1 is a 364 amino acid protein that belongs to the PROCA1 family and exists as two alternatively spliced isoforms. Conserved in dog, cow, mouse and rat, PROCA1 participates in calcium ion binding and phospholipase A2 activity. The gene that encodes PROCA1 maps to human chromosome 17q11.2. Chromosome 17 makes up over 2.5% of the human genome, with approximately 81 million bases encoding over 1,200 genes. Two key tumor suppressor genes are associated with chromosome 17, namely, p53 and BRCA1. Malfunction or loss of p53 expression is associated with malignant cell growth and Li-Fraumeni syndrome. BRCA1 is recognized as a genetic determinant of early onset breast cancer. Chromosome 17 is also linked to neurofibromatosis, dysregulated Schwann cell growth, Alexander disease, Birt-Hogg-Dube syndrome and Canavan disease。