Worked solution: Huang's signed hypercube adjacency matrix proof of the sensitivity conjecture (2019)

Gotsman and Linial (1992) proved the equivalence $\Gamma(H) \ge h(n) \text{ for every } H \text{ with } |V(H)| \ne 2^{n-1}$ iff $s(f) \ge h(\deg(f))$ for every Boolean function $f$. For the former H, one of H and its complement has at least $2^{n-1}+1$ vertices; Theorem 1.1 with $h(n) = \sqrt{n}$ yields $s(f) \ge \sqrt{\deg(f)}$.