Stem cells are undifferentiated cells which usually arises from one cell (clonal) and has the characteristic of self renewal i.e ability to proliferate and differentiate into various styles of cells (potent). Depending upon the potencies there are different sources of stem cells. Pluripotent cells have the flexibility to differentiate into tissues from the three germ layers. There are various sources of stem cells with varying potencies. Pluripotent cells have the ability to differentiate into tissue from all 3 germ layers (endoderm, mesoderm, and ectoderm). Multipotent stem cells may differentiate into tissue derived from a single germ layer like mesenchymal stem cells which form adipose tissue, bone, and cartilage thanks to the limited generation of most somatic cells, stem cells' capacity to replenish damaged somatic cells and maintain a self-renewing reservoir of progenitors is crucial for homeostasis in many tissues of the many organisms. Thus, there is an immense interest in understanding the mechanisms for self-renewal and differentiation in stem cells, given their potential applications in regenerative medicine and studies of human development or aging. This review article emphasizes on stem cells and its various types.

The whole world is reeling under the coronavirus disease-2019 COVID-19 pandemic. It is caused by the novel coronavirus severe acute respiratory syndrome coronavirus-2 SARS-CoV-2. The diagnosis of COVID-19 is based on clinical manifestations history of exposure positive findings on chest computerized tomography CT and laboratory tests. It has been reported that increased release of pro-inflammatory mediators due to an overactive immune system plays a pivotal role in the pathogenesis of COVID-19. This review provides an insight into the different types of coronavirus strains and inflammatory profile involved in COVID-19 with special emphasis on biomarkers such as procalcitonin lactate dehydrogenase LDH ferritin D-dimer and cytokines.