The study's conclusion that tattoo ink causes cancer fails to convince due to major methodological flaws. The sample sizes for the most important analyses (matc

The study's conclusion that tattoo ink causes cancer fails to convince due to major methodological flaws. The sample sizes for the most important analyses (matched twin pairs) were tiny, with fewer than 5 informative pairs for lymphoma. Meanwhile, known lymphoma risk factors like viral infections, alcohol consumption patterns, and occupational exposures weren't properly controlled for. What we're likely seeing is correlation driven by lifestyle clustering - people with tattoos often have different behavioral patterns that independently affect cancer risk, but the study's crude "ever/never" smoking measure and absence of other key controls can't disentangle these complex relationships.