A recent study suggesting a link between melanoma skin cancer and the use of Viagra has caused law firms across the country to marshal their resources for a massive, coordinated legal action against Pfizer over allegations that their blockbuster drug Viagra can cause melanoma.

The latest round of legal scrutiny for the Little Blue Pill came after an epidemiological study was published in the American Medical Association’s research journal JAMA: Internal Medicine. The JAMA article found that men using Viagra had a significantly higher risk of developing melanoma than their peers.

The Viagra skin cancer study checked for cofounders or other factors that could create a false appearance of correlation. However, it was found that erectile dysfunction in and of itself had no link to melanoma. Additionally, the observed correlation was very specific. Viagra users had an increased risk of melanoma, but not other types of skin cancer.

Critics of the Viagra melanoma study have reminded the public than an observational study cannot prove, per se, that two things are connected, only that they correlate. According to science, “correlation does not mean causation.” This means that just because two things relate to on another, they are not necessarily connected.

The classic example that statistics classes use to explain this is that people who wear skirts have a very, very low rate of prostate cancer. While this is technically true, it leaves out several facts that explain this correlation.

However, in the case of the JAMA article, some researchers had already suspected a connection between Viagra and melanoma skin cancer, as the active ingredient in Viagra could interfere with cancer-suppression chemicals in human cells according to theoretical models, which could promote melanoma and other cancers. When an observational study with a large amount of data like the JAMA study matches up with theoretical models, the connection has somewhat more credibility.

However, the legal system has a different role in society, and a different standard of evidence. While science may move slower, evidence like the JAMA study and other research may be enough to convince the court system that patients who took Viagra and developed melanoma could have contracted the cancer as a result of Pfizer’s negligence. As such, several major law firms have begun evaluating claims from Viagra users who were diagnosed with melanoma in preparation for filing a Viagra skin cancer lawsuits against Pfizer.

At present, these law firms are looking for clients who protected themselves from sunburn, took Viagra long-term, and developed melanoma. Such a case would largely hinge on the scientific evidence linking Viagra and melanoma. Additional follow-up studies with different methodologies could provide a more-clear picture of the situation and strengthen the potential cases against Pfizer.