AKT1 and neuroblastoma: SNHG16 affects the activation of the PI3K/AKT pathway in cisplatin‐resistant neuroblastoma cells, and SNHG16 does this by regulating PLK4 expression by sponging miR‐338‐3p and the SNHG16/miR‐338‐3p/PLK4 axis effect.269