No difference: p<0.05 with A axons as n 54.8%; B regression, axons as n 64.5%; C mean g-ratio per mouse 4.4%; D g-ratio at 1 um per mouse 4.6%; E (first version of D) line of g-ratio on axon diameter, at 1 um, per mouse 4.5% Knockout axons 20% smaller, myelin normal: p<0.05 with A axons as n 96.0%; B regression, axons as n 64.4%; C mean g-ratio per mouse 51.0%; D g-ratio at 1 um per mouse 4.0%; E (first version of D) line of g-ratio on axon diameter, at 1 um, per mouse 13.1% Myelin 15% thinner: p<0.05 with A axons as n 99.9%; B regression, axons as n 100.0%; C mean g-ratio per mouse 93.1%; D g-ratio at 1 um per mouse 94.0%; E (first version of D) line of g-ratio on axon diameter, at 1 um, per mouse 93.7%