We report that SALL4 alone, under an optimized reprogramming medium iCD4, is capable of reprogramming mouse fibroblasts into iPSCs. To identify SALL4-direct-interacting proteins, we performed immunoprecipitation followed by mass spectrometry (IP-MS) using MEFs overexpressing WT-SALL4 or SALL4 mutants (ΔZFC1, ΔZFC2, ΔZFC3, and ΔN12) at day 1.