In this paper, the nonequilibriumviscousshocklayerequations have been used to calculatethehypersonicflows over bluntbodies in the fore-body region (including stagnationlineandsonicline).
But Beachy theorized it is needed to make repairs in parts of the body that undergo constant regeneration, as in chronic acid reflux, where Sonic hedgehog works overtime to reline the throat.