A method of formulating a pharmaceutical composition comprising: (a) converting in vitro an animal cell from a first non-pluripotent cell fate to a second non-pluripotent cell fate by: (i) increasing the quantity of at least one reprogramming transcription factor in a first non-pluripotent cell having a first non-pluripotent cell fate to generate a non-pluripotent intermediate cell by introducing into the first non-pluripotent cell having the first non-pluripotent cell fate one or more polynucleotides encoding an Oct4 polypeptide, and optionally one or more polynucleotides encoding a Klf4 polypeptide, a Sox2 polypeptide or a Myc polypeptide, or contacting the first non-pluripotent cell having the first non-pluripotent cell fate with an Oct4 polypeptide, and optionally one or more of a Klf4 polypeptide, a Sox2 polypeptide and a Myc polypeptide, and limiting exposure of the cells to said polypeptide; and (ii) submitting the non-pluripotent intermediate cell to lineage-specific differentiating factors to induce differentiation of the non-pluripotent intermediate cell to generate a cell having the second non-pluripotent cell fate, wherein (i) the non-pluripotent intermediate cell does not significantly express Nanog, and (ii) the cell having the second non-pluripotent cell fate is a cell of mesodermal lineage, a cell of ectodermal lineage, or a cell of endodermal lineage; and (b) formulating the pharmaceutical composition from the cell having the second non-pluripotent cell fate. (a) converting in vitro an animal cell from a first non-pluripotent cell fate to a second non-pluripotent cell fate by: (i) increasing the quantity of at least one reprogramming transcription factor in a first non-pluripotent cell having a first non-pluripotent cell fate to generate a non-pluripotent intermediate cell by introducing into the first non-pluripotent cell having the first non-pluripotent cell fate one or more polynucleotides encoding an Oct4 polypeptide, and optionally one or more polynucleotides encoding a Klf4 polypeptide, a Sox2 polypeptide or a Myc polypeptide, or contacting the first non-pluripotent cell having the first non-pluripotent cell fate with an Oct4 polypeptide, and optionally one or more of a Klf4 polypeptide, a Sox2 polypeptide and a Myc polypeptide, and limiting exposure of the cells to said polypeptide; and (ii) submitting the non-pluripotent intermediate cell to lineage-specific differentiating factors to induce differentiation of the non-pluripotent intermediate cell to generate a cell having the second non-pluripotent cell fate, wherein (i) the non-pluripotent intermediate cell does not significantly express Nanog, and (ii) the cell having the second non-pluripotent cell fate is a cell of mesodermal lineage, a cell of ectodermal lineage, or a cell of endodermal lineage; and (i) increasing the quantity of at least one reprogramming transcription factor in a first non-pluripotent cell having a first non-pluripotent cell fate to generate a non-pluripotent intermediate cell by introducing into the first non-pluripotent cell having the first non-pluripotent cell fate one or more polynucleotides encoding an Oct4 polypeptide, and optionally one or more polynucleotides encoding a Klf4 polypeptide, a Sox2 polypeptide or a Myc polypeptide, or contacting the first non-pluripotent cell having the first non-pluripotent cell fate with an Oct4 polypeptide, and optionally one or more of a Klf4 polypeptide, a Sox2 polypeptide and a Myc polypeptide, and limiting exposure of the cells to said polypeptide; and introducing into the first non-pluripotent cell having the first non-pluripotent cell fate one or more polynucleotides encoding an Oct4 polypeptide, and optionally one or more polynucleotides encoding a Klf4 polypeptide, a Sox2 polypeptide or a Myc polypeptide, or contacting the first non-pluripotent cell having the first non-pluripotent cell fate with an Oct4 polypeptide, and optionally one or more of a Klf4 polypeptide, a Sox2 polypeptide and a Myc polypeptide, and limiting exposure of the cells to said polypeptide; and (ii) submitting the non-pluripotent intermediate cell to lineage-specific differentiating factors to induce differentiation of the non-pluripotent intermediate cell to generate a cell having the second non-pluripotent cell fate, wherein (i) the non-pluripotent intermediate cell does not significantly express Nanog, and (ii) the cell having the second non-pluripotent cell fate is a cell of mesodermal lineage, a cell of ectodermal lineage, or a cell of endodermal lineage; and (b) formulating the pharmaceutical composition from the cell having the second non-pluripotent cell fate.