Do all cells (brain cells, skin cells, liver cells, etc) express the genes or make the same proteins

Codominance is when alleles have the same amount of dominance and both are expressed in a heterozygous individual(ab blood type, roan cow). in a heterozygote with incomplete dominance, the phenotype seen is an intermediate of the dominant and recessive phenotype.(pink flowers when the dominant form is red snd recessive form is white)

Ithink it’s b but not 100% sure