- Absence of linkage between type III protein S deficiency and the PROS1 and C4BP genes in families carrying the protein S Heerlen allele. Espinosa-Parrilla, Y., Morell, M., Souto, J.C., Borrell, M., Heine-Suñer, D., Tirado, I., Volpini, V., Estivill, X., Sala, N. Blood (1997)