The Wall Street Journal has a smart and important piece about a murky side of high drug prices. It looks at the charities that help patients pay their out-of-pocket costs for prescription drugs — but also get hundreds of million dollars a year from drug companies. And in helping the patients cover their costs, the charities help drug companies boost their sales.

The new plot twist: Federal prosecutors are investigating the charities that help Medicare patients, and now donations to charities that help pay for prostate cancer drugs have slowed down — and sales of prostate cancer drugs have plummeted.

Why it matters: There's been a lot of debate about whether financial assistance programs help keep drug costs high, because there's no consequence to the drug companies as long as patients can keep buying them.