  Every large $k$-connected graph-minor induces a $k$-tangle in its ambient
graph. The converse holds for $k\le 3$, but fails for $k\ge 4$. This raises the
question whether `$k$-connected' can be relaxed to obtain a characterisation of
$k$-tangles through highly cohesive graph-minors. We show that this can be
achieved for $k=4$ by proving that internally 4-connected graphs have unique
4-tangles, and that every graph with a 4-tangle $\tau$ has an internally
4-connected minor whose unique 4-tangle lifts to~$\tau$.
