THC-containing vaping products sold under the name Dank Vapes are the most common brand associated with vaping-related injuries, according to a new update from the Centers for Disease Control (CDC). However, there are regional differences in the brands associated with injury and hospitalization, and officials say that one single brand is likely not responsible for the outbreak of injuries.

As of December 3rd, 2,291 patients were hospitalized with vaping-related injuries, now known as EVALI (e-cigarette, or vaping, product use-associated lung injury), in the United States. Only 1,782 of those patients provided information on the products that they used, and of that group, 80 percent reported using vaping products that contained THC at some point in the three months before symptoms began. The number of cases reported each week has declined since the middle of September, according to the updated data, published today in the CDC’s Morbidity and Mortality Weekly Report.

Patients hospitalized with EVALI reported using 152 different types of THC-containing products. Dank Vapes’ products were used by 56 percent of patients who provided that information. Other brands were more common in different parts of the country: Smart Cart, for example, was reported by 24 percent of people hospitalized in Western states, but only 6 percent of people in the Northeast. The brand TKO was reportedly used by 29 percent of people hospitalized in the West, but only 2 percent in the South. Other common brands included Rove, Kingpen, and Cookie.

“By understanding what THC-containing brands EVALI patients are using, we can prioritize our product testing to look for chemicals of concern in those products,” said Matt Lozier, an epidemic services officer with the CDC and an author on the new report, in an email to The Verge.

Vitamin E acetate is still the focus of the investigation into the cause of the injuries. Product testing by the Food and Drug Administration found the substance in 76 percent of the THC-containing products provided by patients who were hospitalized with EVALI. Research shows that it can coat and damage the inside of the lungs. But not all THC products examined contained vitamin E acetate, and some patients hospitalized with the injuries still said they did not use any THC products.

For example, in Indiana, only 69 percent of patients who were interviewed about their product use said that they used products containing THC, according to data also published today in the Morbidity and Mortality Weekly Report.

However, only 29 of the 54 hospitalized patients in Indiana had completed interviews with investigators. The CDC national report notes that they don’t have information on product use by many patients, making it difficult to generalize their findings to the total group of people with injuries. People also may be reluctant to say if they’re vaping THC products, especially if they live in a place where it’s illegal (like Indiana) or are teenagers. The CDC told The Verge that they don’t have data on whether patients have become more willing to talk about THC use over time.

For now, the investigation into the cause of the injuries is ongoing. The new data, though, reinforces the CDC recommendation that people avoid vaping products that contain THC, Lozier said.