Fibronectin fragment to be used for stem cell production

A recombinant polypeptide comprising in the same molecule:

• (a) a polypeptide comprising three repeats selected from the group consisting of human fibronectin III-1 to 7 repeats wherein the III-1 to 7 repeats comprise the amino acid sequences of SEQ ID NO:
• 1, 2, 3, 4, 5, 6, and 7 respectively, or a variant of the polypeptide comprising three repeats selected from the group consisting of human fibronectin III-1 to 7 repeats wherein the III-1 to 7 repeats comprise an amino acid sequence having at least 90% identity to the amino acid sequence of SEQ ID NO:
• 1, 2, 3, 4, 5, 6, and 7 respectively;
• (b) a polypeptide comprising human fibronectin III-8 to 10 repeats comprising the amino acid sequences of SEQ ID NO:
• 8, 9 and 10 respectively, or a variant of the polypeptide comprising human fibronectin III-8 to 10 repeats comprising an amino acid sequence having at least 90% identity to the amino acid sequence of SEQ ID NO:
• 8, 9 and 10 respectively;
• and
• (c) a polypeptide comprising human fibronectin III-12 to 14 repeats comprising the amino acid sequences of SEQ ID NO:
• 12, 13 and 14 respectively, or a variant of the polypeptide comprising human fibronectin III-12 to 14 repeats comprising an amino acid sequence having at least 90% identity to the amino acid sequence of SEQ ID NO:
• 12, 13 and 14 respectively;
• wherein the recombinant polypeptide retains a function of maintaining an undifferentiated state of stem cells, and
• wherein the molecular weight of the recombinant polypeptide is 100 kDa or less.