A new study has come to encouraging new conclusion: aspirin is a big-time boost to cancer treatments.

The pain killer, which works as an anti-inflammatory drug and is available over the counter under common brand names like Bayer, appears to suppress a cancer molecule that lets tumors escape the immune defenses of the human body, according to a New Zealand Herald report.

Experts called this an exciting discovery that could mean a huge difference for cancer sufferers, and come without breaking the bank, as aspirin is available for just a few dollars over the counter.

However, scientists noted that the study doesn’t confirm aspirin’s effectiveness, it merely hints at a new lead for researchers. More trials will be needed to confirm the findings before aspirin is made a routine part of cancer treatment.

Laboratory tests indicate that a molecule called prostaglandin E2 (PGE2) is produced by skin, breast, and bowel cancer cells. Aspirin, according to the study, appears to stop the production of this molecule, allowing the immune system to battle against the tumors.

Tests on mice revealed that aspirin made immunotherapy more effective against malignant cancer.

Prof. Caetano Reisa Sousa of the Francis Crick Institute in London, who led the team, said that the key to stopping cancer may be blocking PGE2, and aspirin may be an effective tool int hat regard, according to the report.

PGE2 may also explain why experimental immunotherapy treatments have been disappointing. PGE2 appears to be the key, as it tells the immune system to ignore cancer cells.

The study was only performed on mice so more work needs ot be done before Cox inhibitors like aspirin are given to humans as part of their treatment, but considering that it’s an already safe drug with a strong track record and that the preliminary indications are good, scientists are excited for the possibilities.