Abstract: A cell population process executed by a computer system, the process including generating cell population data representing numbers of cells in a cell population from one or more probability distributions representing probabilities for cell division in the absence of cell death in successive generations of cells of the cell population, and one or more probability distributions representing probabilities for cell death in the absence of cell division in successive generations of cells of the cell population.

Abstract: In one aspect, the present invention provides a genetically modified cell or non-human organism comprising such cells comprising modified genetic material which when expressed produces a polypeptide co-expressed with a reporter molecule and wherein the polypeptide is associated with terminal differentiation of a haematopoietic cell. Preferably, the genetic material gene is a Blimp allele or a part, fragment or functional form thereof. Furthermore, the identification of the reporter molecule in B-cell lineage cells indicates that such cells are committed to differentiate or have differentiated into ASC. Alternatively, reporter molecule activity in cells of a T cell lineage indicates that these cells are activated. Thus, as described herein, the presence of Blimp in a lymphocyte indicates that the cell is terminally differentiated or is committed to terminal differentiation. Exemplary T-cells include CD4+ T-cells and CD8+ T-cells and exemplary B-cells are ASC.