Slice cable conjecture

Let $K$ be the $(p,q)$-cable of a knot $J$. A knot is slice if it bounds a smooth, properly embedded disk in $B^4$. Slice cable conjecture. The knot $K$ is slice if and only if $J$ is slice and $q=1$. This conjecture would characterize slice cables in terms of the companion knot and cabling parameter; the paper gives obstructions to positive cables being slice, but the stated equivalence remains open.