After the Ice Bucket Challenge and the Invisible Box Challenge, the latest trend to grip social media is the Lemon Face Challenge.

While the Ice Bucket Challenge — in which participants dumped buckets filled with ice and water over their heads — was used to encourage people to raise awareness about Amyotrophic Lateral Sclerosis (ALS) and donate to the cause, the Lemon Face Challenge is a fun and engaging way to draw everyone’s attention to the incurable Diffuse Intrinsic Pontine Gliomas (DIPG), a terminal form of brain tumor that most commonly affects children between five and nine years of age.

According to the Brain Tumor Charity, “DIPG is a type of high grade brain tumor. High grade brain tumors tend to grow quickly and are more likely to spread to other parts of the brain or spinal cord. They are sometimes referred to as being 'malignant' or 'cancerous.'”

So, what do you need to do in this challenge?

First, accept the challenge after being tagged by someone who has already completed it. Next, get a fresh wedge of lemon and bite into it — the whole wedge; just a lick is cheating — in front of a camera as it records your reaction to the overload of sourness.

Lastly, you can choose to leave a comment about your experience but don’t forget to mention what cause it was for. Also mention the name or the Twitter handle of the person or people you would like to tag next for the challenge.

The Lemon Face Challenge was started by Aubreigh Nicholas, 11, who was diagnosed with DIPG in September and has been bravely fighting the illness since. As part of her birthday wish, Nicholas wanted to spread awareness about her illness and the people on social media jumped at the opportunity to help out, Mashable reported. 

The challenge gained prominence when legendary Alabama football coach Nick Saban took part in it and showed his support toward Aubreigh’s Army, which is the charity started by Nicholas and her family to raise money for people suffering from DIPG.

Soon members of other sports teams also stepped forward to take part in the challenge, making it trend on Facebook and Twitter. A group of players with the Los Angeles Dodgers stuffed pieces of lemon into their mouths, gleefully wincing and making all kinds of funny faces. At the end of the video, they tagged their rivals, the Arizona Diamondbacks, to try out the challenge as well and the latter did not disappoint.

However, as Gary Ogden pointed out on Short List, the challenge does lose some of its charm when performed in a group. The objective is to let the camera focus on your expression as you bite into a lemon wedge. When there are more people taking up the challenge together, it is likely the camera will be placed at a distance to get everyone in the frame, which often does not let the viewer enjoy the “sour face” of the participants.

The following are some videos of the challenge:

The Ice Bucket Challenge was extremely successful and raised $115 million for ALS, and it is highly likely the Lemon Face Challenge will follow suit, especially since Aubreigh’s Army already raised $40,000 after just a few days of it going viral.

If you want to donate and be a part of Aubreigh's Army, click here.