-Hematopoesis is known to be guided by more than 20 genes. There are a bunch of mutations that create impairment because of this. Certain mutations will arrest differentiation in different stages and you won't have an effective population of certain cells to carry out a specific function. This commonly leads to lethality of the cell line since critical cells are not produced.
-cytokine super family: example erythropoietin it is a grow factor that stimulates the differentiations of erythopoietic cells. There can be certain mutations in the receptor for erythropoietin. These mutations represent, Intra Locus Genetic Heterogeneity, and phenotype heterogeneity.
-mutation in the cytoplasmic domain of the receptor called a truncating mutation, a segment is blocked off by the mutation. There will be no transmission of signal when erythropoietin binds.