Excel Question on IF Nested Function. Don't know why an element is appearing in the code

While I am learning Nested Function with Excel, I encountered a question that I would like to ask.

The criteria is the following:

1. Increase the backers_count by 5 if:
2. The launched_at_month is January OR September
3. The city is Vancouver AND the country_trimmed is Canada
4. If these conditions are not met, the backers_count stays the same. The code is below:

=IF(OR(condition1,condition2), IF(AND(condition3,condition4), backers_count+5, **backers_count**), backers_count)

My question is why have another backers_count as show bold in the code given another backers_count if False in the end. I removed it for test and returned with false.

Thank you very much for your help and assist.