Extension of Operators from Weak$^*$-closed Subspaces of $\ell_1$
  It is proved that every operator from a weak$^*$-closed subspace of $\ell_1$ into a space $C(K)$ of continuous functions on a compact Hausdorff space $K$ can be extended to an operator from $\ell_1$ to $C(K)$. 
William B. Johnson, M. Zippin