Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021

Capitalize the first word of a sentence
Capitalization
Mechanics

The first word of a sentence should be capitalized. When a sentence appears within parentheses, capitalize its first word unless the parentheses appear within another sentence.

Early detection of cancer increases survival rates. (See table 2.)

Early detection of cancer increases survival rates (see table 2).