If you or a loved one has recently received a diagnosis of non-small cell lung cancer, here are 10 terms you’ll want to know.

Non-small cell lung cancer (NSCLC) and the many terms related to it can be very overwhelming. Trying to keep up with all the treatment options your doctor tells you about can be difficult, especially in addition to the emotional challenges of cancer.

Here are 10 terms to know about NSCLC that you may come across as you make your way through testing and treatment. You might consider bringing this article with you to your next doctor’s visit.

PD-L1 testing measures the efficiency of certain targeted therapies (typically immune-mediated) for those with NSCLC. This testing helps doctors recommend the best second-line treatment options.

EGFR is a gene involved in cell growth and division. Mutations in this gene are linked with lung cancer. Up to a third of all lung cancer cases have a gene mutation present.

T790M is an EGFR mutation seen in about two-thirds of all drug-resistant NSCLC cases. The mutation causes a change in the amino acids, which affects how someone will respond to therapy.

TKI therapy is a type of targeted treatment for NSCLC that blocks the activity of the EGFR, which can keep cancer cells from growing.

The KRAS gene helps regulate cell division. It’s part of a group of genes called oncogenes. In the event of mutation, the KRAS gene can turn healthy cells into cancerous ones.

KRAS gene mutations are seen in about 25% of all lung cancer cases.

An ALK mutation is a rearrangement of the ALK gene. This mutation occurs in about 5% of NSCLC cases, most commonly in those with the adenocarcinoma subtype of NSCLC.

The mutation causes lung cancer cells to grow and spread.

Adenocarcinoma is a subtype of NSCLC. It tends to grow slower than other types of lung cancer, but this varies.

It’s the most common type of lung cancer seen in nonsmokers. It’s also the most common type of lung cancer, making up 40% of all lung cancers.

Squamous cell carcinoma is a subtype of NSCLC. Many people with this subtype of lung cancer have a history of smoking. The cancer begins in squamous cells, which are cells located inside the lung airways.

Squamous cell carcinoma accounts for about 20% to 30% of all NSCLC cancers.

Large cell carcinoma is a subtype of NSCLC that can appear in any part of the lung. It’s usually harder to treat because it grows and spreads quickly. It accounts for about 10% to 15% of lung cancers.

Immunotherapy is a newer treatment for cancer that uses a person’s immune system to help the body attack cancer cells.

Doctors may recommend immunotherapy to treat some forms of NSCLC. This is especially true for people whose cancer has returned after chemotherapy or another treatment.