Security coverage apply to certain. types of work. If you are self-employed, you earn. Social Security credits the same way. employees do (one credit for each $1,260. in net earnings, but no more than four. credits per year). Special rules apply if. you have net annual earnings of less. than $400.
White blood cells (WBCs), also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders.All leukocytes are produced and derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell.onocytes and neutrophils are phagocytic. The number of leukocytes in the blood is often an indicator of disease, and thus the WBC count is an important subset of the complete blood count. The normal white cell count is usually between 4 and 11 Ã 10 9 /L.
Human leukocyte antigen. The human leukocyte antigen (HLA) system or complex is a gene complex encoding the major histocompatibility complex (MHC) proteins in humans. These cell-surface proteins are responsible for the regulation of the immune system in humans. The HLA gene complex resides on a 3 Mbp stretch within chromosome 6p21.