Former DeKalb County CEO Vernon Jones (D) is set to kick off his primary challenge to sophomore Rep. Hank Johnson (D) in Georgia’s 4th district.According to a release from Jones’ campaign, the official announcement will take place at 2 p.m. Friday in Decatur, Ga.Jones most recently lost the 2008 Senate Democratic primary to former state Rep. Jim Martin, who went on to lose the general election to Sen. Saxby Chambliss (R).Jones may not be Johnson’s only primary challenger this cycle. DeKalb County Commissioner Connie Stokes (D) has told local papers that she also intends to run for the 4th district nomination.Jones’ official entry into the race will come one day before Johnson will hold his own re-election kickoff event Saturday.In his own release Thursday, Johnson, who acknowledged late last year that he’s battled hepatitis C for more than a decade, said he’s ready for a re-election fight.“Serious times call for serious representation, and the Fourth District will be well served by a vigorous, positive debate that presents a diversity of views. I look forward to a vigorous campaign and re-election to a third term,— the Congressman said.