The San Francisco 49ers are set to close out their three-game homestand against the Denver Broncos in Week 4. San Francisco enters Sunday's matchup at 3-0 following a 36-30 divisional win over the Arizona Cardinals, while Denver comes to Levi's® Stadium at 2-1 after taking down the Los Angeles Rams in Week 3.

Sunday's matchup will also serve as the 49ers Crucial Catch game presented by Sutter Health, with special activations throughout Levi's® Stadium focused on cancer prevention, early detection, and supporting cancer warriors.

Here are five things to know ahead of the 49ers Week 4 matchup against the Broncos:

1. 49ers Enter Week 4 at 3-0

The 49ers enter Week 4 undefeated following a 36-30 win over the Arizona Cardinals. QB Brock Purdy has thrown for 789 yards and nine touchdowns through three games, earning NFC Offensive Player of the Month honors for September. The offensive line has also not allowed a single sack through the first three games. Purdy is the only remaining qualified QB who has yet to take a sack in 2026.

San Francisco's playmakers have also started the year strong. TE George Kittle leads the team with 174 receiving yards and three touchdowns, while RB Christian McCaffrey leads the team in rushing yards (166) and receptions (13). Defensively, LB Fred Warner has a team-high 33 tackles, and DL Keion White leads San Francisco with 2.0 sacks.

2. Broncos Head to the Bay at 2-1

Denver enters Week 4 at 2-1 after taking down the Los Angeles Rams in primetime at home. QB Bo Nix led the Broncos back from a 16-0 halftime deficit to win the game 30-26. Through the first three games, Nix has thrown for 605 yards, while RB J.K. Dobbins leads the Broncos on the ground with 121 rushing yards.

Denver's defense has recorded eight sacks, led by DL Zach Allen with 3.0. Former 49ers safety Talanoa Hufanga has two interceptions on the season, both coming just last Sunday against the Rams.

Sunday marks the 17th all-time meeting between the two teams, with the series tied 8-8.

3. Crucial Catch Takes Over Levi's® Stadium

Sunday's game will spotlight the NFL's Crucial Catch initiative, which promotes cancer prevention and early detection while helping increase access to lifesaving cancer screenings. The 49ers Crucial Catch game is presented by Sutter Health.

Fans can take part in the initiative at the Sutter Health Gate C plaza by writing handwritten messages of support to cancer warriors, which will then be given to patients at Sutter Health hospitals all across Northern California.

Artwork created during this week's Crucial Catch Art Therapy event will also be featured throughout gameday. More than 30 49ers players joined cancer warriors to paint a community mural and will be rocking their artwork in custom Levi's® jackets while walking into the game. Crucial Catch colors, artwork, and Sutter Health activations will be featured throughout Levi's® Stadium, and special merchandise will be available at the Team Store and online.

Cancer survivor and recording artist Montell Jordan will perform the national anthem ahead of kickoff. Jordan announced he was cancer-free after being diagnosed with early-stage prostate cancer in 2024.

4. Roger Craig Celebrated at Halftime

49ers legend Roger Craig will be honored at halftime with a Pro Football Hall of Fame Ring of Excellence ceremony following his enshrinement as a member of the Class of 2026 this past summer.

Craig spent eight seasons with San Francisco and helped the franchise win three Super Bowl championships. In 1985, he became the first player in NFL history to record 1,000 rushing yards and 1,000 receiving yards in the same season.

Montell Jordan will return at halftime for a special performance of "This Is How We Do It" featuring custom lyrics celebrating Craig.

5. Shanahan Makes 49ers History

Sunday will mark head coach Kyle Shanahan's 167th regular-season game with the 49ers, passing Bill Walsh for the most in franchise history.

Shanahan enters Week 4 with an 85-67 regular-season record since taking over in 2017. Currently under Shanahan, San Francisco has won three NFC West titles, appeared in four NFC Championship Games, and made two trips to the Super Bowl.

Walsh coached 166 regular-season games for the 49ers from 1979-88, finishing with a 92-59-1 record and three Super Bowl championships.