Yes, but it's only one of the components. One MSDS listed a wide variety of solvents and ketones:

Xylene = Dimethylbenzene 42%

Methyl = methyl acetate = acetic acid methyl ester = methyl ethanoate 28%

Butyl = butyl acetate or butyl ethanoate 17%

B-butanone = methyl isobutyl ketone 8%

Isobutanol = isobutyl alcohol = methyl propanol = isopropylcarbinol 5%

Another company uses a different set:

Xylene 52.94%

Methyl isobutyl ketone (MIBK) 25.88%

Methyl ethyl ketone (MEK) 11.18%

Isophorone 5%

Cyclohexanone 5%

The exact mix varies from company to company, which is good because many of these chemicals are difficult to obtain. Nearly any cleanly evaporating paint thinner, thinned with a solvent like xylene, can be made to work.